©Copyright 1999, Fargonasphere.com

SpiderTechnical Tips for Harley Davidson custom motorcycle building and maintenance.

The following is a collection of technical advice articles regarding the legendary Harley Davidson motorcycle in its many forms. The information was won through long hours of experience making mistakes and getting lucky. We make fewer mistakes with experience, but experience comes mainly by making mistakes.

DISCLAIMER:

FARGONASPHERE.COM takes no responsibility for the accuracy or appropriateness of any information you might find here. If you attempt to use this FREE information you do so at your own risk. However, every effort has been made to provide useful information, and we hope you benefit from it.

ALWAYS REMEMBER TO REMOVE THE GROUND CONNECTION FROM YOUR BIKE'S BATTERY BEFORE DOING ANY WORK ON ANY PART OF YOUR BIKE!!!!

IF YOU ARE USING A BATTERY TRICKLE CHARGER AND HAVE ATTACHED THE GROUND WIRE TO YOUR BIKE'S FRAME, BE SURE TO DISCONNECT THE CHARGER AS WELL AS THE BATTERY GROUND WIRE!!!!

Contents

Hidden Virtues of the Shovelhead Motor

Torque Wrench From Hell

Replacing Indicator Lights

Running Lights and Vibration

Sealing Your Carburetor

Variable Jetting

Air/Fuel Mixture Monitoring

Practical Observations of the Jetting Process

Mikuni HSR42/45 Carburetor

Hot Spark Plugs

Spark Plug Gapping and Indexing

Fuel Line Routing

The "Electronic" Ignition Switch

Wires and Vibration

Installing the Hitachi Starter

Wrenching Tips for Starter Pinion Gear

Lubricating Your Shovelhead

Flushing Your Oil Bag

The Ways of Sulfuric Acid

Adjusting Your Primary Belt Drive

The Final Drive Ratio

What's an Oil Slinger?

Tranny Mainshaft Oil Seal

Spokes for Aluminum Rims

Understanding Cams

Tappets


Hidden Virtues of the Shovelhead Motor

The HD Shovelhead motor went out of production in 1984. The motor has always had a bad rep, probably because it was the motor that AMF bought when it bought the company in 1974. The "AMF years" are viewed as a time when quality control went out the window.

But is the bad reputation of the shovelhead deserved? Aren't there some positive reasons one might run a shovelhead motor? First the obvious differences between the Shovelhead and the Evo:

  • Tolerances: Overall the Evo is machined to one thousandth inch where the Shovelhead is machined to five thousandths.
  • Cylinders: The Evo design uses an iron core encased in aluminum casting where the Shovelhead is cast iron throughout.
  • Headbolts: The Evo uses long bolts that extend from the case to the top of the head, where the Shovelhead uses two sets of shorter bolts - one set to secure the cylinder to the case, and the other to secure the head to the cylinder.
  • There are many other differences, but those presented here are perhaps the most significant. Shovelheads can be constructed to be more powerful and more reliable than any Evo. Many racers prefer the shovelhead because it is easier to modify and capable of tremendous extremes of operation. You can get an incredible variety of specialized parts, including high performance cases, pistons, valves, heads and cams for shovelheads. The engine ain't dead by any means, and is considered by many to be the best motor Harley Davidson ever made.

    In racing applications shovelhead cylinders distort less than Evo cylinders because the shovelhead jugs are made of cast iron. When under extreme stress, Evo cylinders (made of aluminum) tend to change their shape due to unequal stress distribution around the head bolts. This results in "blow by" between piston rings and the cylinder wall, and a reduction in power that gets transferred to the pistons. This is a major reason for the desirability of shovelhead motors in racing.

    Although the Evo has higher tolerances, the Shovelhead can be worked on in a home garage without the need for high tolerancing machine tools. In this respect, the Shovelhead is the last HD motor to be designed for the farm-hand. You can wrench the whole thing yourself! (With a little experience.)

    The Evolution engine has earned a reputation for being more "reliable." In reality, the Evo is indeed a little more reliable, but a poorly maintained Evo will be much less reliable than a well maintained shovelhead. The difference is that when the Evo gets out of whack you probably won't be able to fix it yourself.

    You don't need to remove the Shovelhead motor from the frame to remove the heads or jugs. This means you can inspect and replace valves, guides and heads as necessary. You can even hone your own cylinders! The Evo may be more "reliable" but it is also closer to the philosophy of "no user-serviceable parts inside." The twin-cam 88 is even less user-servicable. You need lots of special tools to work on any HD motor after the introduction of the Evo.

    So, you may need to change oil more often, and re-torque bolts, and deal with wear in your valve guides, but you can do these things yourself instead of paying an expensive company mechanic. If you are of the philosophy that a big part of riding a bike is being constantly, intimately aware of how it is functioning, you may find a good set of tools and a well set up Shovelhead motor is just the ticket. Bottom line is what you do when you are stuck by the side of the road and can't take anything apart with limited tools. Evo riders wait for the tow truck. Shovel riders can unbolt stuff and make repairs.

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    Torque Wrench From Hell

    Did you ever need to torque a shovelhead motor's head bolts? If so, you know what a pain that can be if you don't have the right tools. After much struggle, the simple tool shown here was invented. I takes about a half an hour to make one yourself, and you probably have the tools to do it with right in your shop. Click on the image to view the Torque Wrench From Hell.

    Torque Wrench From Hell

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    Replacing Indicator Lights

    The Oil Pressure and Neutral lights on your dash panel may be a potential source of disaster. In aftermarket and most factory models these indicator lights are nothing but 12 volt bulbs mounted in twist-lock receptacles. Unfortunately, the design of the receptacles leads to a high potential for short circuits. A small piece of conductive debris (like a metal shaving) can lodge itself between the inner shell and the dash, causing the light to turn on in error. If the light is intended to indicate that the bike is in neutral you may end up trying to start it in gear. Or, as has happened to me, your oil-pressure light may come on when there is no loss of pressure!

    Fortunately, there is a very simple remedy for the poor design of these lightbulb sockets. You can use 12 volt HIGH INTENSITY LED's to replace the bulbs and sockets.

    A stock socket consists of a shell with a keyway for the tiny posts on the bulb, and a center conductor at the base that makes contact with the center conductor on the bulb. The shell is supposed to be insulated from the dash by a fiber washer. In theory, the shell should never make direct contact with ground. In practice, the shell can easily be bent or contaminated with debris and ground itself. The wiring of the bulbs is with +12 volts to the center conductor on the bulb, and the ground side made or broken to provide the indicated signal. Any light that can handle 12 volts and has its ungrounded side connected to +12 permanently, and its grounded side connected to an oil pressure or neutral switch will do what the stock assembly does!

    So, go to Radio Shack or your local electronic parts supply house and buy two 12 volt automotive quality HIGH INTENSITY LEDs. If you can find a mounting kit for the LEDs make sure it fits into the holes where the lightbulb sockets were installed in your dash. If you can't find a mounting kit, it is possible to use grommets.

    WIRING: As with all solid state devices, you must be careful to limit the current that can go through the LED. Look in the specs for the LEDs you are using and find the maximum current allowed by the devices. You can then use OHM's Law to derive the necessary resistance to put in series with the LED. In case you don't remember, Ohm's Law is expressed as E=I*R, or "Voltage is equal to Current times Resistance." You can find the resistance by simple algebraic substitution: R=E/I, or "Resistance is equal to Voltage divided by Current." Voltage is in Volts, current is in Amperes and resistance is in Ohms.

    Example: For a current of 60 milliamps (ma) and a voltage of 12 volts the required resistance will be E(12)/I(.06) or 200 Ohms.

    If the LED you choose is designed to be used in instrumentation it may not need to have an external current-limiting resistor. Read the instructions that come with the LED carefully.

    Unless your LED panel light assembly has a built-in resistor, you need to place a suitable resistor IN SERIES with the LED, between the +12 volt source and the LED. IMPORTANT: If you don't use a resistor of the proper value the LED will quickly burn out. If you DO wire it correctly, the LED will last longer than the bike, (or longer than YOU for that matter), and it won't be affected by vibration.

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    Running Lights and Vibration

    You know those old-fashioned bayonette bulbs that come with aftermarket license plate and running light kits? Well, those bulbs have filaments mounted on long stalks. It turns out that those bulbs are vulnerable to vibration. The stalks that support the filaments vibrate like tuning forks, and quickly break the attached tungsten.

    I used to go out for a putt and come back to find the running light filament broken, but the stop light filament was always fine. The running light filament was mounted on the longer stalks, so it was evident that the length of the mounting stalks was causing the failure. What I did was to re-wire the stop and running lights using plug-in bulbs, securing the bulb sockets to the brake light housing using velcro strips. Those bulbs haven't failed yet, even though they get the same rough treatment as the older style bulbs. Now I'm saving my money for LED arrays.

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    Sealing Your Carburetor

    Whatever brand of carburetor you run, there are things you need to know if you expect to get efficient performance from your carb. A carburetor is a simple device. It takes air (a gas) and gasoline (a liquid) and mixes the two together in an "aerosol" or fog. The air/fuel mixture can exist in different proportions. If there is more fuel compared to constant air, the mixture is said to be "rich." If there is less fuel compared to air, the mixture is said to be "lean."

    A lean mixture will run your engine HOT, in fact, so hot that your valves and pistons will literally burn up! Whatever you do, especially with a shovelhead motor, avoid a lean condition. Follow your carburetor's instructions to the letter, and carefully dial in your engine by starting with a rich mixture and working toward a mixture that is slightly rich, but never lean. A tell-tale sign of lean running is when the motor backfires through the pipes and sputters through the carb. The motor is trying to tell you something, and it pays to listen. A well set-up carb will give good solid acceleration without backfires or sputtering.

    Things that can go wrong:

    Your carb has gaskets and O-ring seals. Be very careful to install all the seals when re-assembling the carburetor! For example, if you fail to install the O-ring seal that sits on top of the accelerator pump nozzle in an S&S Super E carburetor the float bowl will be at atmospheric pressure and leak fuel constantly around the nozzle. As air is drawn through the Venturi on its way to being mixed with fuel, the air will cause a vacuum over the opening left by the absent O-ring and pull fuel right up out of the float bowl. This appears as a constantly rich condition, with little control offered by changing jets.

    As you drop the float bowl make sure you pull straight down, and avoid tearing the float bowl gasket. If you tear the gasket, the float may not be able to rise high enough in the bowl to close the gas needle valve. If this happens, flooding of the engine will result. You might get "washdown", where raw gasoline washes down over the pistons and into your oil system. Once this happens you should change the oil immediately because gas is a solvent and will destroy your oil's lubricating qualities.

    An air/fuel mixture sensor is a great tool to help you diagnose carburetor problems. The device is based on a sensor that is installed in your bike's tailpipe. You have a welder install a threaded "boss" in the pipe and you thread the sensor into it so that the sensing element is exposed to exhaust gases. The sensor hooks up to an electric meter that measures from 0 to 1 volt. Such meters are readily available on the market. A good source is "Split Second" who can be found on the Web and sell racing engine tuning devices. Here's a link to Split Second

    An air/fuel meter will detect the fuel mixture you are running and enable you to select the right jets to optimize your mixture. It is by far the best way to give yourself some peace of mind on this important issue. It will also detect when your carburetor is leaking, or when you have not installed that one tiny O-ring that makes all the difference in the world. Most important: It will warn you when your fuel system goes south and your motor starts to run lean - BEFORE IT BURNS UP!

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    Variable Jetting

    Unless you run a Constant Velocity (CV) carb you will need to change jets at some time, especially when your travels lead you to radically different altitudes (+-7,000 feet). As you climb into the Sierras you will notice that black smoke begins to emerge from your tailpipe. Your motor will blubber and perhaps your plugs will foul. There you are by the side of the road as the cages roll by and the drivers grin at you and your predicament. What to do? You need to change jets.

    As altitude increases, air pressure decreases. This means that the bike that runs OK at a lower altitude will run richer as it climbs. A CV carb will automatically compensate by maintaining the same pressure inside the carb as outside, but a variable velocity device will meter out fuel at the same rate, but mix less air with it. This creates the rich condition that causes all your problems.

    To change jets you need to remove the plug from the float bowl, drain the gas (making sure you turned OFF the petcock first!) and then unscrew the main jet and replace it with a lower numbered jet. The numbers on a S&S Super E carb refer to the diameter of the metering hole in the jet. Now, the ideal thing would be to change BOTH the intermediate AND the main jets, but to change the intermediate jet you would have to remove the float bowl entirely. At the side of the road this means possibly losing the O-Ring at the top of the accelerator pump tube (see above). Besides, the whole messy operation can be avoided if you install a variable jetting device like Dial-A-Jet.

    The Dial-A-Jet was invented by a racer who got a competitive edge by being able to quickly adjust his carb to accommodate atmospheric conditions at a given race track. For years, these devices have been hidden in carburetors and jealously guarded as trade secrets of racing bike riders. With the Dial-A-Jet you just pull over to the side of the road when your Split Second air/fuel mixture meter indicates you are running rich (or that black smoke starts coming out of your tailpipe), loosen one screw a turn, and dial a leaner condition! And, even better, on your way back down the mountain you can quickly enrichen the mixture in the same way. One danger of changing altitudes is that your attempt to lean out the mixture as you go up can lead to an overly lean condition when going down, and you can wreck an engine by running it for a half an hour in a TOO LEAN condition!

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    Air/Fuel Mixture Monitoring

    Air/Fuel mixture is extremely important to the health of your motor. If you run a motor too lean under load for even a short period of time you risk detonation and meltdown! What this means is that your engine will overheat due to excessive oxygen in the burn and fire at random during the four-stroke cycle. What this means is that your parts will melt or burn, destroying bearing surfaces and resulting in the necessity of costly repairs.

    The air/fuel mixture is the ratio of oxygen to gasoline that gets to your cylinders from the carburetor. A "rich" mixture will have a low air/fuel mixture whereas a "lean" mixture will have a high ratio of air to fuel. You can buy oxygen sensors these days that are placed in the exhaust pipes and send a signal (a voltage that varies from 0 to 1 volt usually) and allow monitoring meters to show the proportion of air to fuel in a running engine's mix. Air/fuel monitoring makes it easy to know for sure that the adjustments you make to your plugs and jets will produce a safe and efficient fuel mixture.

    One very good product is made by Split Second of Santa Ana, California. If you want to see an installation of the Split Second product on my bike, check it out here:

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    Practical Observations of the Jetting Process

    Jetting is more of an art than a science. The use of an air/fuel mixture sensor makes the process more scientific, but it also reveals the complexity of the jetting process.

    You start the jetting process conservatively, making sure that you will be running rich rather than lean. You can get to a good starting configuration by reading your carburetor's instruction manual and selecting jets that are wider in diameter for your engine type and displacement.

    Assuming you have selected a rich combination, you will notice that the air/fuel meter shows rich no matter what you do. Gradually, after a series of trial runs, you will notice that the meter indicates rich while accelerating and bobbles around from rich to lean depending on your throttle position. As you decelerate to a stop the meter will show lean, and will quickly show rich as you accelerate. The thing to observe is that the mixture is NOT CONSTANT. There is no magic value that will show a constantly rich or constantly lean condition. Instead you will observe a range of values that hover around an ideal point.

    Now the artist in you observes this behavior and you get an idea of what might be good for your riding conditions. There are many factors that come into play. Your accelerator pump is one of them. Depending on how you have your jets set up, and how much the accelerator pump is putting out, and how rich your dial-a-jet is set, you will find that hard acceleration forces the air/fuel ratio into the full rich zone, where cruising with a little gas feed runs ever so slightly to the rich side. UNDER NO CIRCUMSTANCES should you run on the lean side while the throttle is open. Full closed on the throttle, coasting to a stop, will run lean, but that is the only time you should see a lean condition!

    Also remember that the actual air/fuel mixture shown by the air/fuel meter may be richer or leaner depending on the temperature of the sensor. This is why it is a good idea to use a heated sensor (four wire) rather than an unheated (two wire) sensor. It is always a good idea to keep things a little rich at the expense of gas mileage in favor of reduced expensive repairs to an overheated or detonated engine.

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    Mikuni HSR42/45 Carburetor

    After jetting the S&S Super E Shorty carb and getting it just right, wouldn't ya know, the gas mileage was about 20 to 30 miles per gallon. Bummer. Seems the Super E runs rich, but gives lots of power at the high end, which sounds about right for the drag strip but doesn't cut it when what you like to do is cruise around and take long trips.

    So, after some research, and on the good advice of the guys at Frisco Choppers, a Mikuni HSR42 carburetor was purchased. It took about nine hours to install. It could have taken less time, but I didn't want to make any mistakes - like have it fall off or leak gas on my leg. After a long Friday evening and into Saturday morning, and a good night's sleep, and some last minute adjustments, the bike started right up but popped through the carb when the throttle was blipped. No sweat. Used a screwdriver to adjust the air screw - in fat, out lean - and in a few seconds the motor started to sound mellow.

    Although the Mikuni is impressive and runs well, it is a little less elegant than the S&S Super E. The Super E is simple in design, with few moving parts. It fits well under the tank and the filter housing doesn't protrude as far. Eventually I found that the mileage wasn't really improved by running the Mikuni and I went back to the S&S because it is easier to adjust and maintain.

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    Hot Spark Plugs

    Have you ever wondered why an open-faced helmet is better than a full-face when you ride a hog? Safety arguments aside, the open-face helmet gives you the ability to hear your engine! Why is this a good idea? You might miss those telltale noises that can signal serious trouble about to happen.

    One day I changed helmets and took a ride. As I was puttin' along I heard crisp pops coming from the engine. The closed helmet had muffled these sharp sounds. After the ride I thought hard about the noise, which was occasionally accompanied by a backfire. I decided I was hearing the sounds of detonation - where your engine is running lean enough to ignite the fuel mixture when no spark is present. I found out that detonation can also be caused by running spark plugs that are too "hot."

    So I went right down to my local auto-supply and bought a couple of Splitfire plugs. After installing these beauties the popping went away and so did the backfiring! Not only that - the bike starts better and runs better. The old plugs were platinum, and apparently were of the "hot" variety, where the Splitfires were just the right heat range for the shovelhead. So far, they haven't fouled, and the detonation problem (which could have seriously damaged my pistons or the cylinder walls) has gone away for good. I bought a couple of spares...

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    Spark Plug Gapping and Indexing

    Each gasoline engine is built with specific characteristics.  The bore and stroke is designed to provide optimum power and torque.  The compression ratio is the ratio of cylinder volume when the piston is at Top Dead Center (TDC) to volume at Bottom Dead Center (BDC).  A high compression ratio (like 9.5:1) will produce more power than a low compression ratio will.  This is because the fuel/air mixture is compressed into a smaller volume before it is ignited by the spark.  This increased compression results in a hotter and more powerful propagation of energy from the burning fuel.

    High compression engines require plugs that have smaller spark gaps.  A smaller gap will create a more predictable spark.  A spark that takes too long to cross the gap will be more likely not to make it, or to make the gap at the wrong time.  This means you get timing problems that can easily lead to detonation.  For a high compression engine you may want to experiment with smaller gaps (on the order of .028 to .025) until you get no misfires at any RPM.  The gapping is very subjective and needs a lot of trial and error before you get it right.  Of course you don't want to gap down to much less than .025 or short out the plug as this could ruin your coil.  Just keep in mind - high compression means short spark.

    Another reason to gap down is to create a more certain spark for kick starting.  A wide gap that might be used with an electronic ignition and platinum plugs may be too wide for the small amount of energy produced by your kick on the starter arm.  A smaller gap will allow a smaller amount of kick to produce a spark and increase the reliability of your kick start shovelhead.

    Indexing means that you use washers of calibrated thickness to raise the plug in the plug hole.  You may want to index if you are running high compression pistons if only to make sure the pistons don't come into contact with the grounding electrodes.  Indexing also enables you to orient the spark in the best position to ignite your mixture.  You can purchase plug indexing kits that will enable you to point the spark at the center of the combustion chamber, favoring the exhaust port.  This is said to be the best position to put the spark, but there is much dispute as to whether indexing does any appreciable amount of good.  In any case, indexing gives you the ability to point the spark so it is visible to the fuel mix.  This can improve the reliability of a kick starter.  For kickers, the spark gap, orientation and fuel mixture are critical.

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    Fuel Line Routing

    If you are getting poor gas mileage (around 25 miles per gallon instead of high 30's) it is natural to suspect the carburetor. The carb may not be the problem. No matter what the displacement of the engine, a carb should get you anywhere from the low thirties to the mid forty miles per gallon. The Mikuni carb, for example, will run fine right out of the box for any displacement from 74 through 96 inches or more. The only exception might be running at high altitude, over 10,000 feet, where it may need to have a larger needle. Even then, you don't need to change anything unless that's where you live. For short trips the carb is very tolerant to altitude and will run rich but not extremely so. If you are not getting good gas mileage and you have tried everything from jetting to adjusting the choke or enrichener you should take a look at the fuel line.

    Is your fuel line running from the petcock to the carb by way of the space between the cylinders? Does it touch the heads, cylinders or case anywhere? Does your chewing gum lose its flavor on the bedpost overnight? Yes? You might have a problem.

    Particularly in the case of the shovelhead, with those iron jugs, a lot of heat builds up between the cylinders. If your gas line runs between them and comes in under the carb, that extreme heat will make the gas expand and force itself into the carburetion system under pressure. This will create a very rich condition. If your bike starts to load up as it heats up you should suspect that the fuel line is getting hot.

    The solution is to re-route the fuel line over the top of the motor instead of between the jugs. You can align the petcock spigot so it points in just the right direction to allow the fuel line to press up under the tanks and come down over the top of the carb and connect to the banjo spigot on the Mikuni. The Mikuni spigot swivels to allow you to do this. You should try to use the shortest fuel line that maintains the greatest distance from the engine. In addition, you should use slitted corrugated plastic heat-resistant tubing that slips over the fuel line to provide an additional amount of insulation and heat protection. I added a couple of strap ties - one at the carb to keep the line away from the rocker box, and one that pulls the fuel line up toward the frame. This arrangement keeps the fuel line in place so it doesn't fall down on the front rocker box.

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    The "Electronic" Ignition Switch

    There are two basically different ignition switch designs used on Harley Davidson motorcycles. The first consists of a brass bar that is attached to the ignition switch center post. The bar is rotated by the centerpost, and its ends snap into place between copper raised buttons that surround the centerpost and connect to the bike's electrical system. The rotating bar connects the buttons together to cause a current to flow between them.

    When electronic ignition systems began to be used on HD bikes, a new kind of ignition switch was introduced. Dubbed the "electronic" ignition switch, this device consists of a rotating copper plate that is attached at its center to the switch centerpost. The plate is shaped so that indentations at various positions on the plate come into contact with copper strips embedded in an insulating material. The plate maintains contact with combinations of these strips. It is really a misnomer to call the switch "electronic" because the switch itself contains no electronic parts - only the plates that slide over each other.

    The difference between the two switches is significant only if you have an electronic ignition system. One thing you DON'T want to happen at any time while the ignition system is operating is to interrupt power to it. The older version of the ignition switch, with its rotating bar, would interrupt current briefly as the switch was rotated to turn on the lights. When this happened, current to the ignition module was interrupted. This interruption of current flow would reset the electronic module. So, the new switch was invented to make sure that the current flowing to the ignition system was uninterrupted when the switch was rotated to turn the lights on!

    MORAL OF STORY: If you install an electronic ignition system on a bike that previously was running points you should replace the ignition switch with an "electronic" ignition switch.

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    Wires and Vibration

    Motorcycles VIBRATE. The plastic insulation on wires used to connect your bike's electrical components together can be removed by vibration. If a wire is wedged between a circuit breaker or other object and the head of a bolt, for example, that wire's insulation can be worn down to the point where it will expose the wire to contact with the bolt head. This can happen faster than you think. To avoid this kind of problem, be sure to wrap all wiring in coiled plastic insulation. You can buy this kind of insulation at your local automotive supply store. The thick insulation will provide a barrier between the wire and any exposed metal with which it might come into contact.

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    Installing the Hitachi Starter

    So, you bought a Hitachi starter and solenoid assembly and you wish to install it on your new custom Harley Davidson softail. You may have also purchased a starter mounting assembly. This article does not cover the mounting of the starter - only the electrical installation of it.

    It's really easy, but there are some things that you should know in order to keep it that way.

    ALWAYS REMEMBER TO REMOVE THE GROUND CONNECTION FROM YOUR BIKE'S BATTERY BEFORE DOING ANY WORK ON THE STARTER, OR ON ANY OTHER PART OF YOUR MOTORCYCLE!!!!

    IF YOU ARE USING A BATTERY TRICKLE CHARGER AND HAVE ATTACHED THE GROUND WIRE TO YOUR BIKE'S FRAME, BE SURE TO DISCONNECT THE CHARGER AS WELL AS THE BATTERY GROUND WIRE!!!!

    Wiring the starter involves the use of one screw connector and one rather large bolted terminal. The screw connector is marked "S" on the right hand side of the solenoid when viewed from the rear. The solenoid is the small housing that sits on top of the starter motor . There is also a terminal marked "R" on the other side, but that terminal will NOT deliver electric current to the starter. The "R" terminal is used in some applications to "Return" some of the current to the ignition system while the starter is being run. You don't need to connect anything to the "R" terminal if you just want to do a basic installation. The "R" designation is confusing because it is easy to imagine that "R" stands for "Relay."

    You wire the +12 volt output of the starter relay to the "S" post. The solenoid is grounded to the frame, so there is no ground wire necessary. The large bolted connector on top of the solenoid housing is used to deliver twelve volts at FULL BATTERY OUTPUT CURRENT to the starter motor. You need to connect the largest battery cable you can find to the POSITIVE (+) post on your bike's battery (that's right, directly to the post) so that the maximum current will be delivered to the starter.

    How It Works

    Inside the solenoid housing there is a coil of wire that surrounds a ferrous (iron) bar. The bar is free to move inside the coil so that when current is applied to the coil the bar is thrust outward toward the starter ring gear. The starter gear is attached to the solenoid core and is pushed toward the ring gear by it. When a certain point is reached in the travel of the solenoid core, the core forces a copper disk to contact two terminals simultaneously. One of the terminals is attached directly to the starter motor, and the other is attached to the high current connection and the POSITIVE (+) post on your bike's battery.

    When the connection is made, the starter gear is already meshed with the starter ring gear. When the current flows through the disk attached to the solenoid core the starter motor turns the gears. Basically, the starter motor and solenoid are just a couple of coils of wire that use electric current to cause mechanical motion.

    What Can Go Wrong?

    There are a few things that can make your starter fail to operate. Keep in mind that, in order to function, a small current (at +12 volts) must flow through the solenoid coil. Then the solenoid core must move toward the ring gear, and carry with it the contact disk. Finally, the contact disk must bridge between the two terminals inside the solenoid housing in order to allow the high current to flow from the battery through the starter motor.

    1. You may have mistakenly connected the +12 volt wire from the starter relay to the "R" post on the solenoid. This will not do any harm, but it won't activate the solenoid either! Be sure to connect the wire from the starter relay to the "S" post on the solenoid.

    2. The starter relay may not be wired correctly. You can verify that it is wired correctly if you test the +12 volt output using a volt meter. Harley Davidson repair manuals contain wiring diagrams that will help you to correctly wire the starter relay.

    3. If you used too much force in tightening the high amp terminal it is possible that you twisted the contact inside the solenoid housing out of position. You can check this by removing the end cover on the solenoid. The cover is located at the rear of the solenoid housing. Inside you will see the solenoid core with the contact disk and the two contact posts. You can see if the contacts are not in alignment, and WITH THE BATTERY GROUND WIRE REMOVED you can test to see if the disk contacts both posts at once. If not, adjust the posts so that they pass current through the disk when the solenoid is thrown forward. When you tighten the high amp post, it is a good idea to hold the bottom nut with a wrench while tightening the top nut.

    If the above suggestions still do not result in a working starter, there may be more serious problems that may require you to have the starter serviced by someone with the ability to test and repair or rebuild electric starters.

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    Wrenching Tips for Starter Pinion Gear

    The starter pinion gear attaches to a splined endshaft on the starter gearbox assembly. The pinion gear is the gear that spins the ring gear attached to the clutch basket. Unless this gear is installed correctly the assembly can come apart and leave you with a pile of aluminum filings and a milled out extension shaft end support!

    When installing the pinion gear on the splined endshaft you will install a splined washer, a spring, a flat washer, the pinion gear, a lockwasher, the extension shaft and the bolt that holds the whole thing together - in that order. The extension shaft is locked to the pinion gear by a lockwasher that fits between the gear and the extension shaft itself. IT IS EXTREMELY IMPORTANT THAT THE BOLT IS TIGHTENED ENOUGH TO COMPRESS THE LOCKWASHER FULLY! If the bolt is not tight, the bolt will work loose and eventually cause the pinion gear to become detached from the endshaft spline.

    It may be necessary to RED Locktite the screw that holds the endshaft to the starter jackshaft spline. You can use a propane torch (CAREFULLY!) to heat the bolt and break the Locktite bond if you wish to remove the bolt at a later date. Of course, WHENEVER YOU USE AN OPEN FLAME ANYWHERE NEAR YOUR BIKE YOU SHOULD DRAIN THE GAS TANK(S) into a legal and safe container.

    The problem is that the endshaft turns in a clockwise direction as the starter is activated. Although the endshaft is held in a bushing, the resistance to turning will cause the endshaft to apply a force in the counterclockwise direction, tending to unscrew the bolt that holds the endshaft in place and compresses the lockwasher. It would be ideal if the endshaft bolt was left-hand threaded, but then it wouldn't mate with a stock starter gearbox endshaft spline.

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    Lubricating Your Shovelhead

    Lubrication is necessary whenever materials are brought into frictional contact. The need for lubrication is found in everything from sex to motorcycle engines (not much difference in Spider's opinion) and providing the proper lubrication for your scoot is the key to remaining free of mechanical trouble. Yes, they are called "troubleheads", but you can greatly reduce the trouble by simply taking good care of your machine.

    A shovelhead motor (manufactured by HD from 1966 to 1984) requires ASA 50 weight oil. The oil should be changed every 1,500 miles after the motor has been broken in. Shovels require more frequent oil changes than Evolution motors. The manual says you should not use multigrade engine oil, but there are differing opinions on this. Some shovelhead fanatics insist that 20/50 weight oil is better than straight 50, reasoning that HD didn't start using multigrade until the early seventies. Since the shovelhead came into existence in 1966, single weight 50 was all that was used. Perhaps HD would have recommended 20/50 weight oil if it were in use when the shovelhead was invented.

    The advantage in using 20/50 is that starting is easier due to the lower viscosity. It's your decision as to whether you want to use straight 50 or multigrade 20/50. A good source of motor oil for your shovel is (of course) Harley Davidson.

    During break-in, the shovelhead lube requirements depend on your break-in philosophy. One school of thought has it that oil needs to be changed frequently. This philosophy is based on the idea that fresh oil provides the best cutting characteristics and allows the mating parts to wear more effectively. Following this philosophy you would do your first change at 50 miles, with subsequent changes at 250 miles until you reach a total of 1,500 miles, after which the motor would be broken in. The other dominant philosophy is that you should do your first oil change at 500 miles and one more at the 1,500 mile mark. The rationale behind this philosophy seems to be that the oil accumulates a lot of metal particles that aid in cutting the metal surfaces. Spider tends to favor more frequent oil changes during break-in.

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    Flushing Your Oil Bag

    It's a pure necessity to change your oil every 1,500 miles when you own a shovelhead motor. But be sure to flush the oil bag every other oil change! If you don't, you risk clogging your bike's oil pump or oil lines and siezing the engine.

    Here's how to do it: Go to your local lumber yard, gas station or hardware store and purchase five gallons of kerosene. The stuff comes in (and must be transported in) special blue five gallon drums. The drums are re-usable. Diesel fuel will work just as well. Be sure to purchase a kerosene pump to make life a whole lot easier. When you get this stuff to yer shop, drain your oil as usual and put a quart or two of kerosene into the tank. You should be careful not to drain the kerosene into the oil pump, so it is a good idea to remove the supply hose and plug the tank with wood dowels. Golf tees might work for this. Every once in a while you should remove the oil bag entirely.

    If you have not removed the oil bag from the bike, with the kerosene in the tank, sit on the seat and rock the bike back and forth so the kerosene mixes with sludge on the bottom of the tank. After some suitable rock and roll, remove the plug and drain the kerosene safely away into a container for environmentally safe disposal or re-use. You might want to do this a couple of more times. There will be black sludge in the kerosene until it runs clear. Make sure all the kerosene has drained out before you fill the tank with oil. Kerosene is a solvent and will destroy the lubricating properties of yer liquid gold.

    It is much easier to do a thorough job if you remove the oil bag from the bike beforehand. In this case, slosh that kerosene around in the tank for fair thee well before you dump the stuff. You should see some black sludge come out. Wash the tank with kerosene until the stuff that comes out is clean kerosene. Again, make sure there is no kerosene left in the tank before you re-assemble the bike and fill the tank with oil.

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    The Ways of Sulfuric Acid

    The stuff used to be called "Vitriol" before its chemical properties were understood. All that was known in the Eighteenth Century, however, was that the stuff would eat holes in damn near anything, and it would just keep eating. And this is the stuff we now use in wet-cell storage batteries that we keep just under the seat on our bike. It's called "sulfuric acid", and it should be approached with sincere respect.

    Just a little of this stuff on your hands will get into your eyes when you rub them. It could leave you blind. If you get a drop on your clothing it will work silently until, when you wash your clothing, you will find holes. Even in indetectable quantities, it will oxidize anything it touches until it is neutralized by combining with the substance it is in contact with.

    Of course you don't want to get this stuff in your eyes! If you do manage to get it in your eyes, call 911 immediately and get to an emergency room. If you have a first aid kit, be sure it has an eye cup and basic solution to wash any acid out of your eyes as soon as possible. The stuff just won't give up. Likewise, you don't want it on your skin or in your mouth.

    If you are using a wet storage battery (with little plastic caps along the top) be sure to attach a plastic tube of the proper size and battery-acid resistant construction to the spill port on the battery. Lead the plastic tubing down to a point below the frame and secure it there so it doesn't bind and get blocked. This way any acid that spills will end up on the road and not on your expensive frame or chrome. One drop on chrome will eat through and rust in no time.

    You should spill some sodium bicarbonate (like Arm and Hammer) to cover any area in which you store or charge storage batteries. Place the batteries on this sodium bicarb matt and it will neutralize any acid that spills out and protect your tools and work surfaces.

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    Adjusting Your Primary Belt Drive

    If you have a 3" belt open primary and you find tranny oil on the pavement where you stop yer bike it could mean that you are loading the tranny's bearings. Your belt may be too tight.

    When properly adjusted, the primary belt should have nearly 3/4" free play when cold. As the motor warms up and you use the clutch the aluminum pulleys will expand and the belt will tighten. When fully hot the belt should still have some free play, but not as much as when cold.

    If the pulleys are not properly aligned, the belt will tend to crawl off or rub against the sleeve on one side or the other. Fortunately, when the clutch basket pulley is properly square with the drive pulley the wide belt will easily keep its position when loose or tight.

    The important thing to remember is that if the belt is as tight as a drum it will overload the bearings and you will eventually have a fluid leak that won't stop, and certain damage to the bearings.

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    The Final Drive Ratio

    Find that you just can't get good gas mileage no matter how you adjust your carb? Does your stroker need to be revved up to 4000 rpm just to go 75 mph? You may need to take a look at your Final Drive Ratio!

    The Final Drive Ratio (FDR) is the PRODUCT of the ratios of your primary drive sprockets (or pulleys) and the ratio of your secondary (or final) drive sprockets (or pulleys). In a formula, this can be expressed as (T/E)*(W/C), where T is Transmission sprocket circumference, E is Engine sprocket circumference, W is rear Wheel circumference and C is Countershaft circumference. Each circumference is measured in sprocket or pulley teeth.

    Given a typical setup, the stock configuration is usually very near 1.5 for the primary, and around 2.2 for the secondary. The FDR for a stock bike might be around 3.3. But wait a minute, you're running a stroker motor. You should know that you don't want to run anywhere near redline, which happens to be at 4,500 rpm. You want to stay below 4,000 rpm to avoid unusual wear and tear (like leaving aluminum on the walls of your cylinders). A stroker wants to run with about a 2 ratio for the secondary. This means a FDR of about 3. This way you will keep the revs down and make use of all that torque. For a typical setup you will be revving at about 2500 rpm when going 60 mph. Now, these numbers are highly general, and depend on lots of factors, not least of which is the diameter of your rear wheel.

    Be CAREFUL not to get the FDR much below 3.0, as this will put too much stress on the drive train components.

    A 10% decrease in the FDR may translate into about a 10% increase in your gas mileage, but not necessarily. Turns out that the energy required to move your bike is the same regardless of what your drive ratio may be. What this means is that the fuel that is burned will be about the same to go a given distance, no matter how much mechanical advantage you obtain. However, there will may be SOME change in your gas consumption. It really depends on the changes you make to your riding style based on the new sprocket ratio.

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    What's an Oil Slinger?

    Back in the good ol' days, when men were men, and gun slingers roamed the West, nobody knew or cared what an oil slinger was. Besides, oil wasn't needed so much as buffalo grease. But if you ride a Hawg you better know what an oil slinger is and use one - or you might find yerself stranded by the side of the road with a frozen clutch pushrod or disintegrated thrust bearing!

    Especially when you are running an open belt primary, you need to keep oil flowing over all the internal surfaces of your tranny. An oil slinger does that quite well. What it is is a metal disc with castellations around the edge (notches) that pick up oil from low down, under the mainshaft and clutch pushrod in the right-side housing. It slings that oil all over the innards of the cover, so it gets onto the thrust bearing and the pushrod. Although the manual says you should fill the tranny to just under the filler opening, if you run an open primary you know that the fluid will end up leaching out of the end of the mainshaft. You can't keep the tranny fluid level high enough to keep that pushrod covered, so the oil slinger can save you trouble and money.

    J&P Cycles sells a kit that includes the thrust bearing, oil slinger, pushrod and fork. The oil slinger slides onto the pushrod just behind the thrust bearing washer and locks into a couple of flats on the rod. For just under thirty bucks you can buy some peace of mind.

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    Tranny Mainshaft Oil Seal

    One day you arrive home after a brisk ride on yer chopper. You notice that black gook is all over yer rear wheel rim and on your chain guard! A puddle of oil is forming under your clutch basket. "What the fuck?" you say.

    Oil puking out of your tranny is a sure sign that your mainshaft oil seal isn't doing its job and needs to be replaced. You need to remove the clutch basket and countershaft drive sprocket to expose the seal. Pry it out with a screwdriver, and replace it with a new seal.

    The oil seal is made of a flexible plastic like neoprene. It has a tension spring surrounding the pressure-fit hole, and a cavity surrounding the spring. Install the seal with the spring and cavity facing the transmission body. When installed, you will see the flat side of the seal facing you.

    The seal needs to be seated firmly by setting it carefully using a hammer and dull screwdriver or flat-ended punch. The oil seal must be seated flush with the bearing behind it, so it is pressure-fit against the bearing. It should be seated to refusal, evenly, but not pounded back so hard as to break the plastic or dislodge the bearing. A sharp tool can break through the plastic, so be careful!

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    Spokes for Aluminum Rims

    When you want to run aluminum rims, such as those made by Akront, you need to be aware of problems that can occur due to the use of dissimilar metals.

    Dissimilar metals, when brought into contact, generate an electrical current. The current comes from electrons that are present in dissimilar quantities in the atoms of the two dissimilar metals. Especially in the presence of a catalyst (like sea water), electrons will migrate from the material with an excess of them to the material that has a relative electron deficit. In the process, an oxide is formed in the sacrificial material. For example, aluminum will rob electrons from iron and create aluminum oxide and iron rust. The chrome on your spokes will flake off.

    When you run aluminum rims you MUST install stainless steel spokes! If you don't, you will find those spokes turn to rust very quickly, with potentially disastrous consequences. The stainless steel spokes cost about thirty bucks more than their chromed iron counterparts, but this cost is minor compared to the cost of a failure of a spoke, a punctured inner tube, and a potentially fatal crash.

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    Understanding Cams

    The cam you are running will have a profound effect on the performance of your motor. This seems obvious, but the lack of understanding of how cams work, and what they do, can rob you of the full enjoyment of your ride.

    A camshaft consists of hardened steel "lobes" that are arranged to raise and lower your pushrods, and open and close the motor's valves. Depending on the dimensions of these lobes, the valves will be held open a lesser or greater distance, for a greater or lesser amount of time. The amount the cam's lobes move the pushrods is called "lift", and the length of time the valves are held open is called "duration."

    Stock HD cams are designed to provide a modest amount of lift for a factory-specified duration, and the stock design is conservative. It is meant to provide good performance without putting too much stress on the valve train. Without too much danger, however, you can improve the performance of your engine by installing a higher lift or longer duration cam. BE CAREFUL, however, not to install a new cam while your bike is under warranty. It may void the warranty!

    There are as many cam designs as there are bikes, it seems. You can get great cams from Andrews, S&S, Crane, and a host of other manufacturers. There are so many options it is hard to make a choice. But you can get a rough idea of what you want if you know how cams work, and how they influence your motor's characteristics.

    If you want to ride around town on a Sunday or take leisurely trips in the countryside you may not even want to know what cam you are running. If the bike is stock you will be happy. However, if you want a little better performance you might want to get a little more aggressive. Using the Andrews cam numbers, you might want to run a J grind, an A grind, or maybe a B grind cam. The J grind will give you better power with a smooth idle, and is just a little better than the stock H grind. An A grind will raise your valves a little higher and keep them open a little longer. It can be bolted in without modifying your heads. An AB grind uses a longer duration exhaust to help your motor run a little cooler, and it gives a little more lift, which improves high RPM (high end) power somewhat.

    If you have high-lift springs, and your valves have been properly clearanced, you can run a more aggressive cam like the Andrews C grind. This cam is about as tall as you can get, but you pay a price in more frequent repairs. Still, on the drag strip this cam will put out monster power where you want it - at around 5000 rpm on up.

    In general, high lift long duration cams are for high power at high revs. The lower lift and shorter duration cams will skew the power curve down so you can get more low end torque at the expense of high-end power. With less aggressive cams you will also have less maintenance, because the springs and pushrods don't do as much work. Less aggressive cams will also give you better gas mileage and a smoother idle. If you use a kicker you will find the bike easier to turn over as well, and because of the increased air velocity you will find the mixture ignites easier.

    Don't think that you need to use an aggressive cam if you are running a stroker motor. If you run a stock grind, or a less aggressive performance cam like the A grind, you will still get a power increase simply from the increased displacement. In addition, you will get improved idling because the higher volume of air flowing through a smaller valve opening will create a higher velocity in the carb at low revs. This improves the idle over what it would be if you were running a high lift cam. So don't worry too much about matching the cam to the displacement or compression ratio when considering the use of a lower lift cam with high displacement engines.

    IMPORTANT: The DURATION of a cam can be shorter or longer depending on your cam's unique specifications. It is important to keep in mind that short duration cams can contribute to a problem known as DETONATION. Detonation occurs when your fuel mixture explodes rather than burns. The subject of detonation is so complex that a full page or web site would be required to explain it fully, so no attempt to do that will be made here. Suffice it to say that extreme detonation can destroy an engine in ten seconds! A high combustion ratio (above 9:1) and/or a short duration (when the valves are kept open a shorter amount of time) can compress the mixture enough to make it explode rather than burn. Normal combustion is not an explosive process. Instead, a "flame front" is generated by the spark plug, and this flame front expands outward, burning fuel and providing energy as it does so. During detonation, however, the fuel explodes, often at the wrong time in the cycle. This puts enormous stresses on pistons and plugs, and can literally blow holes in pistons. Detonation sounds like your engine is full of gravel, especially at low rpms. Detonation can be cured by running the correct high octane fuel, reducing the compression ratio, adjusting for richer carburation, using cooler plugs, increasing the cam duration, adjusting timing, or a combination of these methods.

    Using a high lift cam with a stock or lower displacement engine may be an exercise in futility. It is essential to follow the manufacturer's instructions carefully, because cams often require head work in order to keep the valves from coming in contact with each other or with pistons. In addition, special springs, spacers and keepers may be necessary. Unless you are a drag racer, you should get all you want from your motor by running a stock or modest performance "bolt-in" cam.

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    Tappets

    The "valve train" begins with the cam and ends with the valve itself. Along the way many problems can occur. Tappets consist of a tappet body with a small hole in the side that admits oil to the lifters. A lifter is a device that sits within the tappet body and transfers the motion of the tappet body to the pushrod. The tappets are equipped with rollers that rest on the cam lobes and transfer the positions on the lobes upward to the pushrods, then to the rockers, and finally to the valves.

    You can run hydraulic or solid lifters. Hydraulic lifters have been stock in HD bikes since 1948. Hydraulic lifters receive oil under pressure (12 to 35 psi) from the engine and use that oil to damp the motion of a small piston that is connected to a pushrod. The small amount of oil in the hydraulic cylinder provides a cushion against shock as well as thermal expansion compensation. As the motor heats up the cylinders and heads expand upward. So does the oil in the lifters. With hydraulic lifters you get increased reliability as well as less wear and tear on the valve train - up to a point.

    Hydraulic lifters are just the ticket for average street cruising and touring, but look out when you roll on the throttle and rev that engine! You can exceed the lifter capacity, forcing the oil out of the hydraulic cartridge and possibly damaging your engine. The solution, if you want to push the motor to its limits regularly, is to install solid lifters.

    Whether you install solid lifters or convert your hydraulic lifters to solid, you will be able to run a more aggressive cam, and you will be able to twist that throttle as much as you like. However, you will need to adjust those pushrods more often, and you will need to deal with damage due to increased stress on the valve train.

    It's all a matter of what you want to do with that bike. If you want to spend time on the drag strip and street riding isn't important, you will want to run a high lift cam, and use solid lifters. In fact, if you run an Andrews 3 grind or an S&S 514 on up (for example) you MUST use solid lifters. If you use your bike on the street or for touring you will want the reliability and decreased maintenance requirements of an hydraulic lifter set.

    Shovelhead riders may be interested in upgrading to Jims Powerglide tappet blocks. These blocks are machined to accept Evolution tappets, so you get the benefits of Evo technology, including higher revs and lower maintenance in you shovelhead motor. The kit comes with hydraulic tappets and lifters ready to install. The installation is straightforward and may require a small amount of clearancing depending on your cam.

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