maybe not that bad

[luvmyex]

About 3 weeks ago my motor locked up.I thought i was due to no oil.Well last night i finally started taking it all apart.When i drained the oil there was at least 1 1/4-1 1/2 qts in it.I know thats low but that should be enough to run on and not lock up.I was going to just take the whole engine and let someone look at it.But now i may do it myself.I have the engine out now but havent torn into it.What should i be looking for beside the obvious?Like beside beeing broke how would i know if the rockers are still good?Things like that. Im thinking it may be the cam or related to it.Cause i just replaced the hotcam with the upgraded one.

[YZROOSTINYA]

pitting
etching
cracked items
seized bearings
broken gears

[luvmyex]

GRRR i might be wrong again.Took off the head cover.that went fine.lol but thats almost as far as i got.Cant spin the motor to get the cam sprocket bolts out Called Colby he said take off the cases to see if there is something in the gears.Got the right side off.(no broke bolts Colby) when i removed it something fell out.Not supposed to! From what i can tell the piston has exploded ito lots and lots of little piston parts! I need a bigger socket to get the clutch basket off(after buying a 26mm and needing a 27mm) plus im not sure i want to mess with the bottom end.I may just take off the other case and take it somewhere and let them see what all is wrong in there.And let them do it if its not that much.2 questions.What would cause the piston to blow apart? And anyone know of a trusty builder that wont cost a arm and leg in NC?
BTW thanks for the help Colby if you read this.

[MOFO]

Originally posted by luvmyex
Got the right side off.(no broke bolts Colby) when i removed it something fell out.Not supposed to! From what i can tell the piston has exploded ito lots and lots of little piston parts!

I'm sorry to hear this... sounds like there was more than just a lack of oil to cause this. Good luck with your rebuild!

That sucks. But If you have never done this before i wouldn't take a chance. If it was me i'd try to fix it but if i couldn't id take it to someone before i jacked it up. Im not tryin to sound like a pecker but just don't mess it up more.

[MITrail400EX]

Wow, that really sucks. The only things off-hand that I can think of that would cause piston damage like that would be either preignition (aka spark knock, burned a hole in the piston big enough to cause it to disintegrate) or over-revving. I've never really seen a piston give due to over rev though, usually its a rod that lets go. I wouldn't rule it out. The only other thing I could think of would be too close of tolerances in the cylinder. Maybe it got just hot enough so that where there would normally be enough clearance, it expanded to the point where the piston contacted the cylinder wall, got hotter, expanded more, seized against the wall, and then the inertia of the crank pushed the rod through the piston...wow. thats a lot of "what-if" and "perhaps". Make sure that the shop checks the rod and crank. Best bet would be to replace the rod no matter what. You might also want to have the block and crank magnafluxed. Its when they check for small cracks and weaknesses that visual inspection can't catch. Either way, here's a good excuse to put in that 440 or 465 kit. Good luck, sorry bout your motor!