Is this normal???

[skntsqrl]

Ok I finally got the head off to find out what the clanking sound was and found this. Not sure if its supposed to look like this or if the sleeve has broken off and is sitting somewhere inside the motor.

 

[Surfrjag]

yes the sleeve is supposed to have those two cuts in it, this is where air goes for the transfer ports. your piston is not supposed to look like that though it was overheating for some reason?? did you figure out the clanking sound??

 

[skntsqrl]

Still no clue about the clanking. When I took the exhaust off there was alot of oil in the pipe. I thought the sleeve might have been shattered a little and that what was rattling around dinging up the piston but if that is how its supposed to look I'm stumped. :-/

 

[Surfrjag]

check for play in main and big end crank bearings

 

[skntsqrl]

Oh I did a compression test prior to taking it apart and it only had 92 psi. I'm gonna head back out and check the play in the crank again. I'm pretty sure there wasn't any slack but never hurts to double (sometimes triple) check.

 

[skntsqrl]

Ok there is no play on the crankshaft and no clanking sound when i spin the strator. Only thing I can think is maybe the piston has just worn out the sleeve and is just banging around in it. Do you think I should have it bored out the next size up and get a new piston kit and go from there?

 

[Surfrjag]

probobly, take it to a machine shop and they can tell you for sure what you need.

 

[98blaster+4]

in the first pic it looks like the sleeve is broken on both sides, if you only had 95 psi you need a new piston a size bigger. send it to Ken and he will do you right

 

[skntsqrl]

Ok I have emailed Ken O'connor racing to see what his opinion is. Thank you all for helping me out. I wish there was a closer machine shop to me but I'm in Oklahoma and the only place I can find is a shade tree mechanic and the Yamaha dealership.

 

[bagds101]

ken oconnor ftw. he does great work. best bet is to call him. i can almost guarantee he is going to tell you to call him.

 

[sicivicdude]

That's a completely stock unbroken sleeve. It's either 66mm or MAYBE .010" (1st size) over. I've gotten pretty good at reading bore sizes lately... too much practice at it!

The base of your cylinder looks fine but, from the looks of that piston, the inside probably does not. It needs a bore... but look like everything else will survive

If you've already called Ken, you're in good hands. You'll be back up and running soon!

 

[super noober]

looks like u will probally end up getting it bored and a new piston, not a big deal and u will definately notice a power gain from the fresh topend I:I