Top End = Toast. Need some Advice Pls.

[koster88]

Need a little advice guys...

 

Blew the top end of one of my bikes. Lost compression. tore down the top end, and saw the the pistons we TOAST/melted/etc. I'm not even sure what caused it. Used the same gas I've always been using (93), and used 32:1 as I've always done. Anyway... I thought it was as simple as just having the cylinders either honed or bored (at the advice of the machine shop), buying new Pistons, Gaskets, etc. And putting the top end back together. One person advised me it was a bad idea not to break down the bottom end also, as parts/metal/etc had to have gone somewhere (could have been exhaust, could be in the bottom of the motor.

 

I'm not comfortable yet splitting the cases. I've never done it, and i'm nervous about doing it. I'm Semi Mechanically inclined when it comes to working on cars/basic mechanics, but new to working on my own 2 strokes.

 

Would you tear bottom end apart also?

[Surfrjag]

the bottom end is not dificult at all. just time consuming.. there is a walk through on here that is basically step by step and very easy to follow. even i could do it also consider getting the cylinders ported, it will make your arms longer!!

 

edit: also be sure and replace your crank seals with cometic or oem seals. good luck!

[toytech]

tear it down and clean it and have the crank trued and welded. it's not hard to take apart. and yes new seals.

[BrockMoto]

Sounds like an air leak developed causing a lean condition,I would split them for sure, and do a leak down, before running it again

[bikerjon]

Sounds like an air leak developed causing a lean condition,I would split them for sure, and do a leak down, before running it again

 

 

X2 on that one for sure.