2001 Mountain Cat 800 Burning Coolant

ippielb · Feb 15, 2012

Put the sled in the shop to put new a arms on the sled before it goes in the shop it doesn't leak coolant, finish putting arms on, and then decided to swap the heads from high compression(race gas) to low compression(stock), finish the head swap, and start the sled up and it burns coolant. So immediately i thought i knew what the problem was, when i was swapping heads the inner o rings looked flat, so i picked up new inner o rings and put them on, but I'm still having problems burning coolant.

Sled is a 2001 Mountain Cat 800 Carb with union bay racing engine, slp twins, v force reeds, oil injection delete.

boone · Feb 15, 2012

Sounds to me like one of your o-rings popped out of the groove and is pinched. Pull plugs and look at them. They should be able to tell you which side is leaking then you can just change that side. I use a bit of grease in the groove to help keep the o-rings in place while setting the heads on.

Boone

Idcatman1 · Feb 15, 2012

Burning it or blowing out the hose on the bottle? A pinched inner O ring should be letting compression pressure into the cooling system and blowing coolant out the overflow hose. If it is burning it maybe you spilled some into the engine when you pulled the heads off and it is just running that out the exhaust? If that is the case it will quit in a few minutes after it all gets run through. Antifreeze doesn't lubricate very well so better hope there isn't much in the engine.

ippielb · Feb 15, 2012

boone said:
Sounds to me like one of your o-rings popped out of the groove and is pinched. Pull plugs and look at them. They should be able to tell you which side is leaking then you can just change that side. I use a bit of grease in the groove to help keep the o-rings in place while setting the heads on.

Boone

That was the first thing i checked, it is both sides. I just replaced the water pump shaft seal on my firecat, and i do not want to do another one, it's a pain the in the but for just one little seal. I made sure that the o-rings were set down in the grooves to make sure they didn't pinch, did 3 test sets where i would put the head on it, then put the bolts in and screw them in till they touched the head, and then backed off, just to make sure i wouldn't. They are basically $20 o rings, i'd put the extra time into making sure i didn't pinch them instead of paying $20 for new rings.... ugh

Idcatman1 said:
Burning it or blowing out the hose on the bottle? A pinched inner O ring should be letting compression pressure into the cooling system and blowing coolant out the overflow hose. If it is burning it maybe you spilled some into the engine when you pulled the heads off and it is just running that out the exhaust? If that is the case it will quit in a few minutes after it all gets run through. Antifreeze doesn't lubricate very well so better hope there isn't much in the engine.

It is burning the coolant. Exhaust is white, and is making the brown sludge. Had the coolant cap off and was running the sled and no coolant was blowing out. There is a possible chance that i spilled some, but i wouldn't say much, i pulled the sled over to try and evacuate it all out, and took the air compressor(filtered and dried air) and blew out down there. I ran the sled for a couple minutes max and the white exhaust did not stop.

boone · Feb 15, 2012

Hmmm...is it a complete head you are switching or are you changing out domes? If its domes, is it possible they are messed up or not seated(I have no experience with domes. Just a thought)

Sounds like too much of a coincidence for it to be a water pump seal being that it didn't leak before you did the head swap but I guess its possible.

Boone

ippielb · Feb 15, 2012

boone said:
Hmmm...is it a complete head you are switching or are you changing out domes? If its domes, is it possible they are messed up or not seated(I have no experience with domes. Just a thought)

Sounds like too much of a coincidence for it to be a water pump seal being that it didn't leak before you did the head swap but I guess its possible.

Boone

Thanks for the fast reply, it is full heads the high compression heads are machined, and the low compression are stock heads. I'm going to finish working on my snopro 440 tomorrow, and then bring the mountain cat back in the shop.

Thanks.

ippielb · Feb 17, 2012

Well, i'm afraid the head and o-rings weren't the problem, took everything off, and polished the surfaces of the heads on a piece of glass, torqued everything down to spec, started it up and still burning coolant.

ippielb · Feb 18, 2012

Well, took the engine out today, took the cylinders off and there was some coolant leaking into the case. Glad i took it out, swished some towels through it and cleaned it up, then took the engine out.

Time to replace the water pump shaft seal!

ippielb · Feb 19, 2012

Found the problem!

The mechanical water seal!

The sludge and crap between the water seal and oil seal!

And the damage to the impeller!

fishtank · Feb 26, 2012

900 MC missing coolant

First off I have to say that thats the cleanest looking engine ive ever seen. lol

I am also having an issue with missing coolant. After a ride my coolant bottle will go from full to empty. There are no visible leaks or any in the belly pan or coming out the bottom.

I just read this post so I started my sled up and let it run for 10 mins til warm. The coolant bottle started out full and didnt seem to lose any/much fluid.

I shut the machine off and pulled the plugs. Both were chocolate brown on the ends and I did seem to notice a very small amount of steam/smoke coming out the plug holes.

I also noticed the exhaust was blowing a whiteish smoke/steam the whole time it was running.

However, my question is, how do you know if the smoke/steam is in fact steam, therefore burning coolant?

My sled has always blown blue/whiteish smoke out when I run it. So does every other sled ive used or seen. It smelt smokey like 2 stroke oil burning. The smoke coming out the exhaust didnt seem to dissipate like steam would, therefore I thought it was just smoke.

Booster · Mar 5, 2012

Don't you just love how the 1M bulkhead has to be welded every other year?

Booster · Oct 25, 2012

looks like a wildchild post thats mounted in the wrong postion.....could be leaking from there.

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2001 Mountain Cat 800 Burning Coolant

ippielb

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boone

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Idcatman1

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ippielb

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boone

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ippielb

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ippielb

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ippielb

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