Thanks for the info guys,
I shall address the flywheel forward before pulling the crank then, havent balanced the shaved flywheel so maybe thats the problem. Will try fitting the unshaved flywheel from the 30cc unit (they gave me the whole engine even though I only ordered the short block!)
and see if that helps. If not, I shall try swapping cranks. I guess I could take it to a pro to get the whole assembly balanced, if one is open this time of year.

w8ye is there an easy way to check balance on the assembly without specialist tools? I noticed the fixing screw difference too, although everything else looks the same. My supplier (here in South Africa) is Creative Marketing, they bought in about 40 off 30cc units to 'test the market' else we can only get the 25cc as a complete weed eater unit. I noticed that the jug casting seemed older and slightly tarnished/corroded compared to the crankcase, so they obviously were put together from separate sources originally.

Are you guys running the same carb after the conversion? What is the optimal carb for the 30cc? I did the calc from the formula posted elsewhere and found that a 12mm throat should be sufficient so the standard carb (just over 10mm) *should* be fine. I dont want to lose low end pickup.


Looking forward to putting it in a Green Models Lazer200. You guys should check this kit out, custom made for a 23cc petrol or glow, well made and the Ali tube wing spar has two positions in the fuz, glow (back) or gaz (forward) to compensate for the weight difference, very nice. Email a guy called Paul at [email protected] for more info.