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I put this in the 440 fourm but thought i would stick it in here also. My son was up to the camp this past weekend riding around the lake with his 440 When he thought he fouled a plug he checked both plugs and they were good. When they got it back to camp he pulled the plugs and they were a nice light brown, he put them back in and pulled the rope you could tell it had lost compression. They put it in the trailer and I didn't look at it until last night. When I took the side panels off the first thing I noticed was the head had turned a gold color on one side and the coolant reservoir was empty. There was no coolant on the ground when he brought it back so it must have all puked out on the lake while he was moving.
Two studs (one plate) ripped out of the track and went through the front heat exchanger. I had 60 lb on both sides we pulled the heads and the o-rings on the domes were melted out. Piston's look fine and can't feel or see any scoring in the cylinders. I was going to replace the o rings and see what I get for compression. If the motor got hot enough to turn that head cover gold should I be concerned about anything else if I get the compression back ??? Any help would be appreciated.
 

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Trax said:
I put this in the 440 fourm but thought i would stick it in here also. My son was up to the camp this past weekend riding around the lake with his 440 When he thought he fouled a plug he checked both plugs and they were good. When they got it back to camp he pulled the plugs and they were a nice light brown, he put them back in and pulled the rope you could tell it had lost compression. They put it in the trailer and I didn't look at it until last night. When I took the side panels off the first thing I noticed was the head had turned a gold color on one side and the coolant reservoir was empty. There was no coolant on the ground when he brought it back so it must have all puked out on the lake while he was moving.
Two studs (one plate) ripped out of the track and went through the front heat exchanger. I had 60 lb on both sides we pulled the heads and the o-rings on the domes were melted out. Piston's look fine and can't feel or see any scoring in the cylinders. I was going to replace the o rings and see what I get for compression. If the motor got hot enough to turn that head cover gold should I be concerned about anything else if I get the compression back ??? Any help would be appreciated.
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if it got that hot you can loosen ring locating pins on the pistons.
 

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Getting hot could of taken the temper out of the rings to
 

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id definitley pull the cyls off and take a look, and consider puttin two new pistons in it because like what was said, it could loosen the locating pins and also be prone to other problems. id make sure my wrist pin bearings are ok too, if it got that hot. and if your going to spend $$ on rings, its more for piston and rings but worth considering
 

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I have overheated a sled before and not that badly eitherjust a head bolt had come loose and lost a little coolent BUT when i checked everthing out the cylinders had gone oval just enough to loose about 15 pounds of compression and lost my top end on lake by about 10 to 15 mph.The cylinders looked actually good,no scoreing that was noticable but the Nik coating had obviously wore down on the sides of each cylinder enough.No easy fix had to have them recoated,not cheap.Just something to check out a little more closely with a micrometer.
 
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