Piston cracked in half

[Rendal]

Just picked up an 04 800 summit for the wife, nice clean shape, seized motor (2200 miles). Took a quick look inside and the clutch side dome of the piston is cracked in half and chunks are missing on both sides of the crack. Most of the shrapnel is sitting on top of the piston, Sorry no pics.

Was hoping it was just a top end but I have a feeling it's more than that.The spark plug is also smashed in so I'm assuming maybe a bearing went south or a rod broke ?
Any preliminary thoughts/opinions before I take it to my mechanic on friday?

Thank's
Rendal

 

[Van Epps]

Guess I should have read your post closer. Sounds like you may have damaged the bottom end. Good luck to ya!

 

[sledsrock]

Broken piston is what closed the gap on the plug, you'll need to go all the way down to the crank to get all the debris out. Cylinder damage? Crank bearings okay? To do it right, you'll have to split the cases and start from there....good luck!

 

[Ox]

On an '04 you may as well just be on the safe side and put in a reman crank from Doo. Forget the piston incident - the bearings were ready to let go anyway. And that may possibly have been the cause to begin with.

I lost the mag side doo to the mag bearing going out, and then running lean I guess. ???

Replacing the crank covers you both ways - Contamination and old bearings.


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Think Snow Eh!
Ox

 

[Rendal]

Thanks guys, we'll be tearing it apart tomorrow night. I will update with full extent of damage.

 

[Rendal]

Update

Well it's shortblock time! First thing we did was pull the head and you could hear the thermostat rattling in there, sure enough it was in two pieces. It was doomed from there, but according to my mechanic the amount of destruction in there seems to be due to over revving.
Last owner said the sled blew on the trail, we found the clickers were set on #6. Oh well , I was hoping to just slap a top end in it but there is so much damage it would probably come out pretty close pricewise to rebuild as to pick up a new shortblock. I think I'll take the peace of mind and go new.
The cylinder was cracked near the base the piston was held together by the ring, both skirts completely missing. A chunk of the skirt was pocking through the bottom of the case and the rest must have disintegrated as it was pounding the crap out of the dome in the head . The crank seemed ok but who knows.

Anyway, Check those thermostats!

All the dealers are closed for the long weekend Anybody know the going rate of a shortblock is in BC or even Washington state? I guess I also need a head, might as well upgrade while I'm at it. Any suggestion will be appreciated.


Thanks,
Rendal

 

[BIG JOHN]

why a shortblock??? just get a crank /pistons...unless the cases have holes...BJ

 

[sledsrock]

why a shortblock??? just get a crank /pistons...unless the cases have holes...BJ

Hey BJ,

I believe a chunk of skirt poked through the lower case..........I had that problem on the 670 and had the case welded, worked fine afterwards.