cold seize

[garv08]

Could someone please settle an on going argument (4 years now) for me, is it possible to "cold seize" a motor, then be able to start and run it for another 20 miles before it does a total melt down?

I was with a group, we began a ride one morning, it was 10F degrees out, same ol routine, we started our sleds at the same time, then proceeded putting on head gear, aprox. 5 minutes. I was last one to leave camp on lake, so I was playing catch up, gruop was ripping across lake.
My 97 600 XCR triple, was running across the lake then just shut off, like a kill switch, then I couldn't pull it over it sat for 2-3 minutes then started right up and ran flawless for 20 miles then melted.

Center piston was nuked, hole melted thru top of piston at exhaust port.

 

[maxwell]

Not a cold seize if it warmed up for 5 minutes. Sounds more like an oiling issue or something. Pretty common for a seized motor to unlock itself after cooling down. Our group had a locked up m7 a few years ago. I let it cool for 10 minutes, spun the clutch in reverse and it came free. Fired it up and drove it 30km down the mountain to the truck


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[Old Boy]

Good Morn I think that cyl was running lean. Cold seize side wall are side of piston would have been damaged.

 

[pfi572]

Not cold seize. Running on the lean side and it always seems to appear on middle cylinder .
Holding it pinned across a lake is always the spot it shows up .
Lots of cool air due to speed and not quite enough fuel .
At least you know where the line is for jetting.
Lol

 

[Bnorth]

I dunno sounds like a cold seize to me. Fire up the sled, get it warm then start ripping and getting lots of snow on the cooler, sends cold water to the jug and it tightens right up around that warm slug. Possibly a lean issue as well but the first seize sounds cold to me.

 

[cnelson6]

Any pictures of the piston that will help.

 

[neilsleder]

I dunno sounds like a cold seize to me. Fire up the sled, get it warm then start ripping and getting lots of snow on the cooler, sends cold water to the jug and it tightens right up around that warm slug. Possibly a lean issue as well but the first seize sounds cold to me.

My same thought. Started going before the thermostat opened up and cold seized the middle cylinder which is the hottest one.


Sent while sitting on the toilet when I should be working!

 

[slededjr]

Five minutes doesn't really mean anything either. Depending on ambient temp and temp of engine when you first fire it up. There's days mine will idle for almost 10 minutes and just gets around 100 °F. I've seen lack of oil cause what you're describing and cold seizure also. Would have to see pic of piston.

 

[tex78]

It's a lean burn down if it melted the piston top.

Cold seized is at the 4 corners of a piston ( either side of the intake and exhaust ports ) cause the piston expands there and squeezes.

sent while I should be drinking twisted teas

 

[Modman]

Since the piston had a hole in the middle of it at the exhaust port side, its 95% certain it was lean. The cooling effect of the intake charge generally keeps the intake side of the piston cooler, the hot spots in a lean motor show up on the exhaust port side....post-combustion....when the temps are hottest. A cold seizure would have resulted in a 4 corner score and mechanical damage along the sides of the piston and the cylinder walls, more than a hot spot on the top of the piston.

Holes/melted areas in the top of a piston are generally a sure sign of "Detonation" or pre-ignition. Excess heat in the combustion chamber and on the piston dome cause hot spots that pre-ignite the fuel mix before the spark, when the flame fronts collide, the sound is a "ping" or detonation. Too lean of jetting will cause detonation, so will bad fuel or not enough octane. This is why triples always have staggered jetting on the center cylinder. Something could have gotten into the carb jets and caused it to go lean, or the carbs could potentially need sychronization and the center was opening farther than the others. You could have an air leak on the center jug, or any number of issues (fuel delivery, pipes, etc).

You likely got it hot enough to seize it to the cylinder, (piston expanded beyond clearance tolerance). Once it cooled and freed up, there was a compromised area on the piston dome in front of the exhaust port that was probably thinner or mis-shapen after the seizure, the 2nd time around it overheated sooner, causing the hole. My theory anyways.