Kawi2strokes.com Forum

It is all in when the firing occurs in relation to the charge rate of the capacitor. We want firing to occur when the capacitor is fully charged, not on the way to full charge.

Actually, point type magneto's work the same way, fire at the top of the sine wave, for maximum spark output level.

That's the rub. Damon did it many years ago and swore he just relocated the pin and all was good. That's why I spent 2 weeks fiddling around with it. I finally just took the chance and moved the key-way and that fixed the problem.

_________________
Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

The H series racers used a different variation of magneto, with only one rotor to do both charging and timing, with no battery charging windings. The same issue between rotors and crank taper key locations existed.

I now remember that in the instructions to convert the street bike H2 engine to run in the H1R chassis, there is a section on how to mount the H1R ignition to the H2 crank taper. Just phase the rotor on to the taper, and tighten down real good, no key needed.

There were 3 ignition sets for the H1R, and, 7 H2R in all, with even more H1R types for the H1R-LC, and H2R for the KR750. In the case of H series cross use, we'd often use opposing rotors without keys in place. Never did have one spin on a taper. The race rotors were about half the weight of the street bike pair.

The factory race ignition rotors, magneto windings and ignition box sets were identified by different color paint "splotches" to keep the parts matched up. It was pink, green, red, blue, white, etc. We tried to keep the colors secret, they also gave the curve packages as well. It wasn't uncommon to see a pink stator with a green box set for Talladega, all white for Laguna, blue, green for Daytona, white, red for Mallory Park, ect.

Getting back to the OP's cap, I wonder if one of the plastics people that make stuff for our bikes couldn't do a reasonable, great quality cap for the early distributor, for those wanting to stay running the original ignition systems.

I wish someone would.

From an earlier request, I have been modelling the H1/A distributor cap in Autocad, to 3D print. I have not worked on it in some months but did some more today, spare time and all that. I have carbon rod for the center button I need to machine or grind a step on, will print the cap in two halves and bond together. With some careful work it will look original, at the very least offer a low cost alternative for a replacement part to keeps bikes running. Screen shot of the Autocad model here.

_________________
1974 Kawasaki H2B 750, 1981 Yamaha XV750 Cafe, 1986 Kawasaki KDX200, 2003 Honda XR100, 2004 SDG140. 2006 Ninja 500R Turbo intercooled fuel injected.

I have to add a short info on a car distributor cap that has a LOT of problems. As we all know, GM and everyone else started with point type distributors, and low quality caps. Along the way, we now have Ryanite cap materials, and better caps because of it.

One company did what was called a "Cross Fire Cap", one that had cross over circuitry inside the cap to put all the wires for one side of the engine, on one side of the distributor, etc. The original Cross Fie company made a good cap for low perf systems, with actual spark plug wire between the terminals, to do the rearrangement.

Of course, when the company was sold in later years, the new people looked to maximize profits, and changed the cross over wire material to literally a carbon core printed circuit.

This was, and is a total disaster, rendering the caps plain junk.

I hope the new Kawasaki caps will use some sort of RF shielded top quality conductor from the rotor terminal to the wire socket, that would be excellent.

The cap I have here has aluminium terminals inside, I had planned to use brass instead, and silver soldered to brass plates that have the piercing threads in them, need to find some sharper set screws for the piercing screws. I will use as large a wire guage spring for the current transmission from the coil plate to the carbon center pin as I can get away with. Cap will be printed in two upper/ lower halves so I can assemble and bond the plates and guts inside before bonding. A technique called Acetone smoothing can make the outside look like the original smooth moulded part, I have not experimented with it yet, but I'm sure it's not rocket science.

_________________
1974 Kawasaki H2B 750, 1981 Yamaha XV750 Cafe, 1986 Kawasaki KDX200, 2003 Honda XR100, 2004 SDG140. 2006 Ninja 500R Turbo intercooled fuel injected.

Acetone smoothing will help smooth the ridges of the layers of filament, but it won't be smooth like an original cap. It's possible that you could hand sand a part right after printing, and alternate coats of spray paint with sanding, and get close to an original finish, but since the cap is under an aluminum cover, that seems like a lot of trouble to go to.

_________________
If it surges, that's normal, upshift.

Of course, the copper terminals are top quality, but aluminum works just as well when taken care of. My small body HEI conversions make an honest 28K to 31K volts on average, and no adversity with aluminum terminals. One thing that helps is to use a good conductive grease on the terminals to help stop ozone burn in on the terminals to stop that buildup.

McMaster-Carr​ is a good source for all sorts of fasteners and other materials, that is where I get my bulk stainless steel bolts, screws and other stuff for the conversions I do.

From MSD...
"With the introduction of our 20 Amp extreme HEI module, we needed an HEI cap and rotor that could withstand the high output. The answer was to mold our own HEI cap, rotor and coil cover. The cap and rotor will fit our HEI Pro-Billet distributor, PN 8365, plus will work on stock applications. The carbon rotor button in a stock HEI distributor cap has very high resistance. When the high voltage of an MSD 7 series ignition is added, this resistance builds up heat and can actually melt the distributor cap. The solution to this problem is the use of the MSD low resistance HEI bushing which will pass the secondary voltage from the distributor cap to the rotor without excessive heat buildup."

They have a sintered bronze button that is an upgrade, so I am looking at not using carbon but a copper or similar material.

_________________
1974 Kawasaki H2B 750, 1981 Yamaha XV750 Cafe, 1986 Kawasaki KDX200, 2003 Honda XR100, 2004 SDG140. 2006 Ninja 500R Turbo intercooled fuel injected.