As with most things RCMK .... there later parts are better than the former
Primary coil they work the same and WOULD STAY with the RCMK coil when used on RCMK cast cases, a Zen coil needs plastic trimmed & brass rivet head taken of too work.

As for SECONDARY coils, Zens GREY coil is near failure proof and a GREAT part.
RCMK's secondary with the writing on it tends to need tighter S/P gaps @ .015" to keep from misfiring at high rpm. The newest "Non Written on" coils seem now to be just fine and will fire .022-.024 gaps no problem.

Talking SECONDARY coil that has the plug wire and not the generator/trigger coil

The two systems are for practical reason the same, have really found no benefit in mix & matching ... sadly

Scott
My son and I are building a engine (from scratch) for his boat using:
- RCMK sx 254 case
- RCMK 1mm stroker crank
- J&G V2 top end kit

I have ordered a new Zen grey coil and red 'pickup' I was hoping to use.

DO I use the Zen flywheel or the RCMK flywheel - does it matter?

Do u need to use Zen ignition with Zen flywheel and same with RCMK?

Thanks

Randy

Canadian Hot Rod RC Boats wrote:Flywheel do work with either, tho I WOULD base my decision of which flywheel to use based upon WHO's crankshaft is in those cases .... so the tapers best match