I assume your asking about the piston to deck difference? It looks deeper in the hole than I have seen. Does it have two base gaskets on there or an extra thick one?
I have rebuilt many 2 strokes in my day. and have never seen a piston this far in the hole at tdc. don't get me wrong, this bike rips! this just looked a little off to me.
It's quite normal for there to be a gap .... I'm sure if you placed a ruler across the top of your piston it would be level with the top of the jug .... It also has to accommodate expansion .
uh, yeah. Just looked it up , I'm about .100" over ! Lets start from the beginning.
I bought this bike for next to nothing, case was split due to a blown output shaft bearing (the one behind the front sprocket) guy said everything was there. well the crank and clutch was missing. no biggie. purchased a used crank off eBay along with a new rod and bearings sent this to RB to have it assembled, since he was doing my head and carb anyways. never had a chance to compare crank nor rod side by side so it looks like a wrong part was put in. piston is a stock piece. I guess this means I can run 87 octane has then ! I've been riding this bike for about 2 years this way. it runs good. I just gotta spin in like a 125 . oh well. I'm still gonna send it !
following photo from phospher site (good job to him!)
Since you gave about zero background info, did you just install the rod kit? What have you JUST done and how did it get to the point in the picture? Thanks.