Drew burton on here is running a mwsc flywheel and running in the cp class... he's doin ok with it... that engine has got some torque so gear the tractor to use it... and I've never put a tach on my little kawaski but I can just about gaurentee with a stock cam and a billet flywheel its not turnin over 5000... just like where im intek stopped... and probably just about every other stock engine out there... but wont know till you get a tach for it...