Andrew Wellman
ArboristSite Operative
I have been reading up on two stroke performance tuning and have some grasp of the cause and effect of changing ports. I am going to dig into a chinese 372 cylinder for my first attempt. I have read that a 2mm drop in intake port or 2mm trim in piston is a safe standard to start from? Do you you raise the exhaust the same to balance the motor? What I understand is that this increases the peak hp rpm, thus faster chain speed, thus more work being done? The other beginners school of thought is to just widen the ports keeping them elliptical/beveled, were this keeps the timing the same, but increases the volume of mixture thus increasing the hp at stock max hp, rpm. I made a degree wheel and will be learning to use it but are there some rough guidelines for porting a work saw. Finally, what is a reasonable expectation for performance gains, 5% gain in hp or 20% gain in hp. Is this more work than its worth, and just a geeks hobby
any one?
any one?