Originally Posted by
wingracer
It will run badly because the cut out in the piston skirt allows the crankcase to be opened to the exhaust at the top of the stroke. This kills your crankcase compression which is what helps fill the cylinder. Also, it's probably going to hurt your compression since it was broke in the other way around.
I agree. I have since moved on from this engine. On the first practice day of the season I always use my weakest engine. Because at that time of the year the weather is still nasty 60's and 50's.