I'm swapping my s4 block for a s5 j-spec. I was just getting ready to put the s5 counterweight on the flywheel, when i noticed that the s4 one i just removed, was damn near identical.



Anyone know what the difference is supposed to be?? It looks like there are a couple extra holes drilled in the "s5" one, but other than that they are the exact same.



Should there be any more difference?

 

I would imagine that the counterweights, while similar, are balanced for the specific engine. It could be just a small difference in weight between the models, but thats all it would need to throw of timing.



Of course thats just my two cents. I'm not that well aquanted with the Rotary engine, yet...

 

the s5 rotors are lighter therefore the cw needs to be lighter, i argee its hard to tell em apart though



mike