i noticed wiseco only makes 11:1 pistons for a 300 and only 12:1 for a 250x. my question is are they the same piston and just the different stroke effects the compression ratio? thanks

 

The pistons are different part numbers so I assume they are different. Doesn't seem that they need to be different though. The pin might be in a different location is all I can think of.

 

the 250x piston is taller due to the smaller stroke

 

im bring this back as i didnt really get the answer i was looking for

 

Maybe Wiseco can answer your question. It's a little strange to me too. The bores are identical but the stroke is longer on the 300. There must be some reason the 250X has more compression. I know that the 250 has a decompression valve and the 300x does not. And if you've ever tried to kick a 250X without the decompressor valve being hooked up, it almost hurts.