No one can deny that those four cylinder motorcycles from Japan are street roasters, but they do have a common weakness. The ignition systems operate off the end of the crankshaft just like your Briggs & Stratton lawnmower. As you might have guessed, a top cycle drag racer noted this shortcoming and decided to fabricate a distributor to cure it.
Stop and think about it for a second. If the engine is revved to ten grand, the ignition system has to contend with point float, crankshaft and breaker plate flexing, and coils which fire one dead and one compression cylinder at the same time. At higher operation, the coils can’t have enough time to reach saturation which means the fire to the plugs tails off. And, since one set of points actually fires two cylinders, the greater spark will go to the cylinder on exhaust stroke. Electricity always seeks the easiest route.
On the other hand, R.C. Engineering’s kit features a distributor which runs at half-engine speed and fires only those cylinders which are on compression. The wasted spark to the dead cylinder is eliminated. Just pure common sense will tell you the translates to improved efficiency, hotter spark (especially at high rpms), better plug and point life, improved gas mileage, easier starting, and easier tuning. The R.C. kit uses a Mallory distributor featuring self-lubricated precision bearings with the utmost in advance and retard action. This installation can make a world of difference in the all around performance and operation of your cycle whether it be street, drag, or even touring. This system is that much more advanced.
Magnum Manufacturing has been testing a number of ignition systems since their turbochargers enable to bike rider to achieve higher than redline rpms, so we picked up on this test. This particular unit from R.C. Engineering is called the Hi Performance Kit which consists of all hardware, a coil, silicone wires and boots, a Mallory distributor and an engine adapter. R.C. Engineering is located at Dept. S/C, 16216 South Main Street, Gardena, California 90248 and the suggested retail price of the HP kit is $212.50. That may shock your shorts a little, but how does that line go, “How much do you want to go fast?”
The installation of this kit is really simple. If you can tune a cycle you can bolt this distributor kit onto your bike. Toolwise you are going to need some metric wrenches, 30 weight oil, a torque wrench, and a timing light.
First step is to remove the gas tank and point cover. The engine should be rotated until the number one cylinder is on top dead center on the compression stroke. This can be verified by being sure both valves are closed and the timing is on the “T” mark behind the breaker plate.
The 13mm head bolt which retains the advance mechanism and the screws which retain the breaker plate housing can be removed. The entire assembly can then be removed from the cycle by unplugging the wires up by the fuel tank.
The first part of the kit to be installed onto the bike is the degreed timing hub which locates onto the engine crankshaft using a dowel pin for timing. The work and drive gear and key can now be positioned onto the hub. A longer, 13mm bolt supplied with the kit is then installed at 18 foot/pounds to retain this assembly.
A small timing pointer is added to the very top down and the initial timing (between the second and third hash marks from the left) is set by bumping the rear wheel with the bike in gear.
The distributor is then fitted into the housing, being sure the key drive engages. This can be checked by trial testing the distributor rotor. Proper positioning of the distributor is achieved by rotating the body until the cap clip next to the condenser is above the mounting stud. The rotor, as shown in the photo, is then positioned directly above the rubber plug. The complete assembly can be mounted onto the engine.
Now the distributor must be removed and 1.25 ounces of 30 weight oil added for gear lubrication. The distributor is then dropped back into place. Since this is a worm gear drive, the rotor will now be properly positioned if it is pointing over the rear set of points. With it all the way down into place, fit the hold down bracket and nut snugly, not tight, at this time.
For timing, the distributor body is turned counter-clockwise until the back set of the points begin to break (.001-.002 inches). A buzz box or static timing light is very useful for this operation. This setting produces 15 degrees at idle and a total of 40 degrees of advance at 3,000 rpms and above.
The cap is replaced and ignition wires added. Number one is farthest from the engine and the others are installed counter-clockwise. Last of all, the single coil is positioned under the tank replacing the original dual set. The negative pole of the coil feeds the distributor wire, the positive goes to the ignition switch.
As soon as the engine is fired you will notice the first difference – it idles much faster indicating a more efficient use of the fuel and wicking the throttle will instantly tell you that a big change has been made. Besides that, there is this wicked looking hunk of performance adorning the side of the cycle. It’s definitely a good mix of improved looks and performance for the fours.
