What happened?

[oldtimer]

2001 800 summit, 3000km Only had about 3 hours this winter. Son-inlaw took to mountains, 2 miles from staging siezed up. Tore down tonight, flywheel side cylinder scored. Rings not broken, plugs nice and brown, piston domes look good, nothing jumps out. First time tearing 2 stroke apart. Boots look ok (previously replaced)
Any ideas on cause of failure. Thanks

 

[neilsleder]

Is it scored up on four spots around the piston? My guess he didn't warm it up and cold seized it. Thats how you get four corner scoring.

 

[neilsleder]

Put a picture of the piston up that will help to.

 

[0neoldfart]

Likely a cold seizure, need a photo of the piston as stated above.

 

[Modman]

2001 800 summit, 3000km Only had about 3 hours this winter. Son-inlaw took to mountains, 2 miles from staging siezed up. Tore down tonight, flywheel side cylinder scored. Rings not broken, plugs nice and brown, piston domes look good, nothing jumps out. First time tearing 2 stroke apart. Boots look ok (previously replaced)
Any ideas on cause of failure. Thanks

Oil pump failure or cold seize. T-stat could have been stuck closed, then suddenly released as he got it to full temp up the trail. Its 13 yrs old so an oil pump failure or sticky t-stat is not out of the question. If he didn't warm it up then cold seize is very likely.

 

[oldtimer]

If stuck thermo or n/g oil pump would we not see damage to both?

Thanks

 

[mxzretta]

Looks like a cold seize. Never let it warm up enough

 

[oldtimer]

Any shops in south Edmonton for parts and machining?

 

[boots]

Not that I know. St. Albert , absolute power I beleive.


Sent from my iPhone

 

[96sherm]

Thats what my 2011 Assault looked like. Reason for mine going like that was the PTO side crank seal was wrecked from flying crank bearing parts... Some food for thought...

 

[kootenaycat]

my '01 800 Summit did the same thing 2km from the truck a few years back. But it stuck so hard it took out 1 jug, had to hammer the piston out of the jug lol! Found the waterpump impeller not in good shape, think the Doo dealer said it was a press onto the shaft and was slipping? Cost me about a grand to rebuild the motor and I did 75% of the labour myself. Took the bottom end to the dealer to have the crank trued and all seals replaced. Jug would have been the most expensive part but found a good used one for a big bottle of whiskey.

 

[Cat401]

Is it scored up on four spots around the piston? My guess he didn't warm it up and cold seized it. Thats how you get four corner scoring.

Cold Sieze??? Really?....2 miles down the trail??

By 2 miles, everthing should be warm, no?

 

[neilsleder]

Cold Sieze??? Really?....2 miles down the trail??

By 2 miles, everthing should be warm, no?

It could of scored it up then get progressively worse and have taken that long to totally wreck it. Heck T&T voided my warranty cause they told me I cold seized my motor and put on 40 miles before miles before it seized. So apparently anything is possible! Lol

 

[KatMan]

Cold Sieze??? Really?....2 miles down the trail??

By 2 miles, everthing should be warm, no?

thats probably when the thermostat opened.

Stopped my cat middle of the day on the mountain, popped hood up, cold day, ate lunch, 15 minutes later fired up the hill, cold seize in about 1 minute. Cold seize can happen anytime if you have a slug of cold water in the heat ex-changer and your thermostat is closed. didn't think it could happen once you're already riding, but can as well. what happens is once thermostat opens, slugs in all cold water, cylinder begins to contract. BOOM. always make sure your exchanger is warm and circulating before riding. if not, sudden rush of cold water can seize your engine.

PS one more notch against your son in law.....

 

[Modman]

thats probably when the thermostat opened.

Stopped my cat middle of the day on the mountain, popped hood up, cold day, ate lunch, 15 minutes later fired up the hill, cold seize in about 1 minute. Cold seize can happen anytime if you have a slug of cold water in the heat ex-changer and your thermostat is closed. didn't think it could happen once you're already riding, but can as well. what happens is once thermostat opens, slugs in all cold water, cylinder begins to contract. BOOM. always make sure your exchanger is warm and circulating before riding. if not, sudden rush of cold water can seize your engine.

PS one more notch against your son in law.....

x2 on this ^ exactly what I posted on another thread that got deleted. After lunch is a prime time for cold seizes.

Cold Sieze??? Really?....2 miles down the trail??

By 2 miles, everthing should be warm, no?

He says 2 miles but what was the real distance..2 kms? The tow back always seems longer, even if its only 200 yrds.

 

[oldtimer]

Thanks to everyone for all the great feedback and information.

As for the son-inlaw?
He owes me big. haha

 

[crwdplsr]

I have a complete motor here still in a complete sled that I have for sale, considering parting it out. Can also get you replacement pistoins and a renicked cylinder and top end gasket kit for about 700 bucks. Can usually do a top end job like yours for under 1200 labor and parts in. Mike 1-403-704-0825