bad jetting and air leaks will not hesatite to ruin a piston JS but yea a 240 kit would definatly compliment a 3mm crank. just hone and put it together and doo heat cycles and comperssion test and check for air leaks and it should be a very fast and capeable bike with little problems
Egad guys, really, is ths helpful?
To the original poster, YES, you can run a 3mm stroker crank with a stock top end.
You have to shim the cylinder to make squish distance right. Vito's gives you a 1mm basegasket shim plate to do this.
There are some small issues with port timing and such, but this will get you running.
About some of the other "advice".
2 stroke cylinder heads do not wear out. They can get damaged, but do not wear out.
A 240 kit is not needed for a 3mm crank. You can install a 3mm crank with any bore, it will not wear or break the piston.
Scarring the piston is not related to a 3mm crank. Probably not related to 40:1 oil ratio because I run that too.
You do not need to change oil ratio for weather, pick an oil and ratio that suits your needs and stick with it.
If your piston, ring and bore are in good condition, you can reuse them with the 3mm stroker,
but like Larry said, this may be a good time to replace a worn piston and bore.
Guys, if you really don't know for sure, why are you chipping in with "advice"?
Claiming it was a "a joke" afterward doesn't help anything either.
Tell us you experiences, give us the details, but be careful, some of us really don't like the smell of BS.
Steve