2007 summit Cold seize

[Jason]

My son and I headed up to the mountains for the first time and his machine blew up 4km up the trail. Seized solid(couldn't pull rope) drug it back to the truck and after it cooled down t turned over fine and started. We shut it down and when we stripped it down it looks like a cold seize on the PTO side. Cylinder and piston scored on four corners. The machines were running for 20 mins before we left the trucks so I don't think this was it. Anyone have any ideas what else may have caused this? I hate to rebuild it and have it just happen again. Temp. was about -20 and groomed trail.

 

[1100]

sounds like it could be a cold seize as the 07 revs run no t stat so even though you had your coolant warm all it takes is to jump off into the deep snow and get a shot of cold antifreeze. Happened to me on an 05 RT which also has no t stat stock, mill one into the head or put one in off of an XP

 

[tex78]

huh i have a temp gadge and a 07 800r and have never cold sized her or seen big temp swings like some say.....

 

[thumperracing]

sorry to hear that

 

[HagmanMod1]

let mine warm up good got 6km from home and she locked up. it broke free and i drove it home they tell me cold seize

 

[Shibby!]

Poorly positioned filter and snow coming in through the intake?

Was it deep snow or just trail? Was the trail riding behind the "mist" of another sled?

From what I know, 4-corners is a clear indication of cold seisure too.

 

[imdoo'n]

huh i have a temp gadge and a 07 800r and have never cold sized her or seen big temp swings like some say.....

well no wonder, your blind in one eye and can't see out of the other.

would the temp gauge react that fast jeff, would have to be a significant temp change.

 

[tex78]

well no wonder, your blind in one eye and can't see out of the other.

would the temp gauge react that fast jeff, would have to be a significant temp change.

its right at the top out to the bottle and has no t stat.... so yes it should

 

[rmiller]

I bought a 07 800 summit this spring. Started and ran well when i looked at it. Then earlier this winter started it let it warm up, when for a little jaunt in the field maybe 1KM. The engine siezed, let sit for awhile, started again no problem, went back home let it idle for a while, drove around the yard just great. Then proceded down the subdivision and seized again, broke the pull start even it was soo tight. Bottom line, it ended up being the infamous crank bearing issue. The sled had 1600km. So BRP rebuilt crank new pistons gaskets etc. hopefully it will be running again soon. Thanks to Tom at Mots Maching in St Albert.
Hope this is not your situation, but thats what happened to mine.
Cheers
Rick M.

 

[Jason]

It had seize marks on 4 sides of the piston so I'm assuming cold seize. We were on the trail and he was following another sled and there was a fair bit of snow dust. I'm assuming its not the crank by looking at the piston, correct me if I'm wrong. Second question is I got the mono block cylinder re-nikaseled(Spelling) but the piston rebuild kits I have it came with 2 head o-rings not the one piece oring for both cylinders. I'm thinking this kit is for the 2007 800HO engine not the 800r mono block, is everything else in the kit the same? Pistons the same?

 

[rusty]

I disagree with a cold sieze. if there are four corners of the skirt scuffed that indicates a overheat situation.

your piston skirt was allowed to expand to the cylinder walls.

but this is hard to tell with out pics.

 

[Jason]

bump

 

[troy]

the pistons for the 800r are different than older 800s I have seen r engines having trouble from not enough piston wall clearence I have two 07 800r summits with no topend trouble BUT lots of crank troubles 1500m like clockwork my sled has 5000 miles without topend trouble but three cranks

 

[Jason]

I've got the pistons out now, looks to me like they both overheated. Attached are a couple pictures.

 

[troy]

By the look of your wristpins alittle shy on oil as well

 

[tex78]

I've got the pistons out now, looks to me like they both overheated. Attached are a couple pictures.View attachment 87178

View attachment 87179

View attachment 87180

is that the intake side of the pistion or exhaust?

also u might want to install a temp gadge when u put her back in.... its nice too see the temp before the idiot light and engine burble starts [ the ecm retarts stuff to save it...

my temp wire broke [ for the aftermarket gadge ]and we were ridin and all of a sudden it won't rev and is messin around... look down and the temp light is on....

 

[slednecks11]

Sorry to hear about that

 

[Jason]

Both pistons are scuffed all the way around. Worse on the exhaust sides.

 

[teeroy]

my '08 800R seized on me early this winter, had been riding it all day and on the way back to the trucks it piled up. I was following a couple other sleds, plenty of snowdust in the air and ambient temp was around -18c. after tearing it down it also looked like a cold sieze on the pto slug, with most of the scuffing on the intake side. also found the plate the airbox slides onto was off the pto side carb a little.....I think because they run so lean at 1/4-1/2 throttle any kind of snow ingestion while exhaust temps are at 1250 is deadly. heard lots about the lean spot but finally saw it myself after I installed a koso guage when I installed the new motor....wow. no more cruising at that throttle position.

 

[maierch]

my '08 800R seized on me early this winter, had been riding it all day and on the way back to the trucks it piled up. I was following a couple other sleds, plenty of snowdust in the air and ambient temp was around -18c. after tearing it down it also looked like a cold sieze on the pto slug, with most of the scuffing on the intake side. also found the plate the airbox slides onto was off the pto side carb a little.....I think because they run so lean at 1/4-1/2 throttle any kind of snow ingestion while exhaust temps are at 1250 is deadly. heard lots about the lean spot but finally saw it myself after I installed a koso guage when I installed the new motor....wow. no more cruising at that throttle position.

It is pretty appalling how hot the EGT gets on a stock motor cruising at 6-7000 rpm. Riding on a rough trail it's difficult to keep the EGTs below 1200 without blipping the throttle and making the trail worse.