National Banshee

Were your old pistons just loose in the cylinder or did they break? I have done lots of these with broken skirts that crack the cases.

Cylinder compression wont tell you everything you need to know. Piston to cylinder clearance will determine whether or not you need a rebore. Most 2 strokes today will run just fine untill the piston breaks. Depending on how the air filter was maintained, most engines will go 2 years of hard running. Some only make it 1 month. Air fiter maintenance, premix type and ratio, and engine warm up will dictate how long yours will last. If you think its time, tear it down and measure the clearance. I'm sure we all know someone who has broken the skirt off the piston and punched it throughh the cases!!!!!!!!!