Well I thought you guys might enjoy this.

I was prepping the wife's bike for this season by warming it up. I let it warm up and reved it a few times and then all of a sudden all hell broke loose. I didn't even rev it very high is what has me stumped right now.

I'm tearing into the bottom end tomorrow night. I'm still not sure what caused what at this point. Any ideas?

Looks like it had been burning a little oil. I had noticed a few puffs of smoke out the exhaust. Those are the original valves so I'm sure it was leaking past the valves. DARN! I should have taken a good pic of the cylinder. It still has hash marks and I beat the hell out of that thing. Check out how clean that piston is though. You can still see the markings on it from when it was new.

It's an LTZ450 by the way with a high comp piston.

Last pic:

ouch. that dosen't look friendly.

i think the bolt failed... then it went down hill from there..


why is that valve sticking out? did you drop a valve? or did it just bend it when it nuked it self?

The bucket is cracked/bent. The valve isn't bent and it didn't touch the piston. I can't figure that out. The bucket is holding the valve open. Those are two cracks you see in the bucket. The top part stayed down when the valve tried to close and the center part rose slightly. That is what created the half moon shape you see.

it could just be the pic but it really looks like 2 of the valves hit the piston.. but it is most likely the pic.. did any of the valve keepers come out?


btw what did the timeing chain look like? any damage or fall apart?

If you had thrown yourself on it before it exploded, you could have saved your whole platoon...


I feel your pain. Although my pain wasn't as bad. That looks like it's gonna be expensive.

i get a sharp pain in the wallet just looking at those pics!

Did someoene say second hand motor

The cam chain was perfect. I was concerned about that also.

Too much to repair so I pucked up a used Alba built 470 stroker motor f0r $1000 that I'm going to drop in it. The first thing I'm replacing in that sucker is the cam chain because it's stretched to the max.

I still haven't torn into the tranny to take a look in there yet.

I'm in no hurry right now as I have my LTR at the dealership being sold as I've ordered a Polaris RZR and it's due in next month that the wife and I will be riding. I'm getting too darn old to ride the way I'm riding and I need to slow down but the RZR will still quench my thirst for power and speed when I need it to.