2001 blaster rebuilt top end and still low compression... out of ideas

[Bryan Alderman]

I have a 2001 blaster 200cc 2stroke. It’s stock from my knowledge. I bought it not running and have since replaced, Cdi, stator, intake boot, carb, tors elimination, had the original cylinder bored and replaced with wiseco 67.5mm piston and all new seals and gaskets. There is no play in the rod whatsoever. With everything hooked up I get 80psi with my compression tester and it will fire off and putt twice and die. I know I’m supposed to get 110+ to be where it’s needed. But when I did a leak down test the only trouble was the reed gasket and it was super small. So I unplugged the leak down tester and plugged in my compression tester and got 110-115psi with the exhaust port still blocked with rubber from the leak down test still in place. Any ideas or explanations? Would a bad Fmf fat pipe cause this? I’m at a loss and can’t find any answers or info anywhere... thank you for any help.

 

[Daryl Schmitz]

Do you by chance have the piston in backwards?? The arrow should face the exhaust port.