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1928 Shovelhead Project Part IV

Charge This Puppy By Compu-Fire

Photos: Tina Fairless

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One of the best aspects of building bikes nowadays is the integrity of the components. If you get the right mixture of components together and take care with the wiring and assembly, you'll have a bike as reliable as factory stock. That's one of the reasons Bandit has moved to using Compu-Fire electrical components on most of his bikes. First, because even he can install them, and most of all, because Compu-Fire has been building electrical components for years. The stuff doesn't break.


Take, for instance, this charging system. The stator slips firmly in place over the engine sprocket shaft race area and Compu-Fire suggests that you use the stock fasteners with a drop of red Loctite to ensure it won't ever come loose. Compu-Fire alternator plugs are the protruding variety from the late-model design. Carefully oil the plug and slip it into place, then replace the plastic bridge and fasten it with blue Loctite. If you have new cases, make sure there are no sharp edges on the plug opening. File if necessary. Then with the shaft seal .090 shim in place, use a wire feeler gauge to determine that you have at least .060 of clearance between the rotor and the case.


With each Compu-Fire charging kit for Shovelheads or Evolutions comes a thrust washer that goes on the outside of the rotor on chain primary systems. It may not be necessary on belt drive primaries. Mr. Gillihand from Compu-Fire recommends that you have a direct ground to the engine cases. Compu-Fire charging systems are the series type, unlike the shunt variety. The difference is that a shunt type drives the charge to ground if the battery is satisfied, causing the alternator to heat up and constantly work. The series type shuts the stator off when the battery is satisfied, which allows the unit to cool. The hot wire goes directly to the battery through a circuit breaker, or to your ignition switch on the hot side. In this case, the regulator was positioned with the coil between the tanks so the plug wire had to be extended.

That covers the basics of installation. Now here are the specs: Compu-Fire manufactures two versions of its charging kit, a 32 and 40 amp. From 1970-'75, stock charging systems were rated to 15 amps; from 1976-'80, they were 17.8 amps; between 1981 and 1988, they jumped to 22 amps; and finally, in 1989, skyrocketed to 32 amps. Now fuel injected models run 38-amp systems. So the two systems cover the lot.


We'll get into wiring after paint and chrome. The ignition system is Power Arc. The timing module is in the nose cone and the coil is also positioned under the seat with a chunk of angle iron. This system is about as clean as you can find.

Next week we'll hit the final sheet metal as we close in on paint and chrome, and the lovely Princess Lena, daughter of the rich and powerful Rick Fairless, king of the Strokers Ice House plantation, makes her move on the hapless Bandit. --Wrench

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