Unique two cycle engine

[Stretch]

New to site. Got a question that maybe one of you more knowledge gurus might be able to contribute to. I have an old cushman trackster, it has a somewhat unique engine, it is a 29 hp two cycle with horizontally opposed cylinders that fire at the same time. The ignition consists of the old point type operating off a cam configuration on the crankshaft. The amplifier burned out a few years back so I replaced it but the new one (old stock) also quit nearly immediately. At $200.00 each I went a different route. I removed the amplifier and installed two automotive canister type coils, one for each cylinder and wired in series equipped with a ballast and condenser. The machine ran great for several years and then both coils quit. I replaced them with the same type and my toy is back up and running great again. My question is: is there a coil type one might recommend which might be better suited for this configuration? Any challengers? LOL, also when the throttle is returned to idle the engine keeps revving but if left eventually and slowly drops back to idle level. Might this be the diaphragm operated valve not effectively reducing the fuel supply?

 

[mark20]

New to site. Got a question that maybe one of you more knowledge gurus might be able to contribute to. I have an old cushman trackster, it has a somewhat unique engine, it is a 29 hp two cycle with horizontally opposed cylinders that fire at the same time. The ignition consists of the old point type operating off a cam configuration on the crankshaft. The amplifier burned out a few years back so I replaced it but the new one (old stock) also quit nearly immediately. At $200.00 each I went a different route. I removed the amplifier and installed two automotive canister type coils, one for each cylinder and wired in series equipped with a ballast and condenser. The machine ran great for several years and then both coils quit. I replaced them with the same type and my toy is back up and running great again. My question is: is there a coil type one might recommend which might be better suited for this configuration? Any challengers? LOL, also when the throttle is returned to idle the engine keeps revving but if left eventually and slowly drops back to idle level. Might this be the diaphragm operated valve not effectively reducing the fuel supply?

i can try lol
for the coil i reccomend you try to keep your system as is (no idea how you got it to work lol)
but if it has a fly wheel (or make one like a motoirzed bike, they work too lol) they you could get magnets and put 2 coils, (like a lawnmower) one on the bottem and one on the top, then place the magnets on the fly wheel. and advace or retard the timing as needed
byou might want to clean the diaphraphm valve. and see if theres any junk in it (also check the povit point)
lube your throttle cable as i could be that its resisting the spring and not fully returning.

hope this helps!

 

[JerboaJohn]

clean carb/s, ^ free up throttle and resistance. if the gaskets are as old as I think they are dried up and crusty, maybe leaking air into the engine creating a lean condition.
I'm gonna go out on a limb and say you might be able to mount 2 of these coils. they work for 18-22hp cushies and save some $.
https://www.amazon.com/D5TE12029AB-Internal-Resistor-Ignition-Holland/dp/B01AAQPLRK - $26 no need external ballast resistor. wire em in parallel, not series. I saw a thread on gas golf carts for this info: http://www.buggiesgonewild.com/gas-golf-carts/45947-1960s-cushman-truckster-ignition-problem.html

 

[Will'smotobikes19]

Am opposed that fires in both sides at the same time? How does that work? Must have an interesting crankshaft. I know there were inline twins that fire at the same time. But that’s up and down not a flat twin. Interesting

 

[SubtlePepper]

You might want to check for an air leak between the carb & intake manifold, that's a common cause of the engine not returning to idle