sled has run perfect for 2 years, and today, went lean.(burnt down)

backcountryislife · Feb 20, 2010

So the sled has run great for about 2 years, but today it just siezed up.

Pipe is WHITE, only pulled one set of plugs, WHITE.

Digging into it in the morning, no big deal doing a top end (I hope that's all) but I'm not sure what would have happened, egt was 1240 right before it went, sled normally runs 1220-1260 wfo, so no big deal.

I'm thinking stopped fueling, or I had a coolant leak, never seen a Y pipe that white before.

Any ideas for good things to check? Also, how do you check the fuel pump without running the motor? I want to make sure I didn't lose fuel pressure, but don't want to wait till I start the motor again to find out.

KSH · Feb 20, 2010

backcountryislife said:
So the sled has run great for about 2 years, but today it just siezed up.

Pipe is WHITE, only pulled one set of plugs, WHITE.

Digging into it in the morning, no big deal doing a top end (I hope that's all) but I'm not sure what would have happened, egt was 1240 right before it went, sled normally runs 1220-1260 wfo, so no big deal.

I'm thinking stopped fueling, or I had a coolant leak, never seen a Y pipe that white before.

Any ideas for good things to check? Also, how do you check the fuel pump without running the motor? I want to make sure I didn't lose fuel pressure, but don't want to wait till I start the motor again to find out.

If you loosen line there should be some residual pressure, not very scientific.
If motor fulls over, just pulling it will build pressure.

killerrf · Feb 20, 2010

well you can run a 12v battery hitched up to the fuel pump to run it and see what the psi is.

backcountryislife · Feb 20, 2010

motor will move a tad, but VERY little, so I can't test it that way.

I'll give a 12v batt. a try.

Any ideas on what would be likely?

I hope it's obvious, I hate putting something back together & HOPING you fixed whatever was the problem in the first place.

dobson · Feb 20, 2010

backcountryislife said:
motor will move a tad, but VERY little, so I can't test it that way.

I'll give a 12v batt. a try.

Any ideas on what would be likely?

I hope it's obvious, I hate putting something back together & HOPING you fixed whatever was the problem in the first place.

a pressure test may help, i had the same issue on a 900 cat, turned out it was the case started leaking at the reed housing. cost me two burndowns before i pressure tested it.

FCR112 · Feb 20, 2010

Sorry to hear it, that sled rrrips. Did you get out ok

sidewinder · Feb 20, 2010

I had a base gasket failure on my tm7 and it turned the inside of the pipe white and scored up the slugs. When you pulled it apart what did the pistons look like? Mine had 4 corner seize marks on them and the skirts were scored pretty good where the coolant washed off the oil.

Evolution Powersports · Feb 21, 2010

Backcountry, what sled? Last year we had 2 identical 06 M7's burn down within 100 yards of each other on the same day. Both had RKT 15:1 heads. Both ran flawlessly for a year and a half with the heads and they ran fine all day. It was on the home stretch back to the trailer that they went down. Both sleds mag side piston. Strangest thing I ever saw...

Only thing I can come up with is bad gas.

We cleaned up the bores, got new mag side pistons and put the stock heads back on. My dad is still running his - but complains about the lack of power because of the stock compression.

snowmobiler · Feb 21, 2010

not enough oil will do a white hot before the hot light turns on.

mmsports · Feb 21, 2010

What is you sled?

This is why I always tell my customer to run 2 gal of race.....

I think this what happened. Or crank seal.

Bone said:
Backcountry, what sled? Last year we had 2 identical 06 M7's burn down within 100 yards of each other on the same day. Both had RKT 15:1 heads. Both ran flawlessly for a year and a half with the heads and they ran fine all day. It was on the home stretch back to the trailer that they went down. Both sleds mag side piston. Strangest thing I ever saw...

Only thing I can come up with is bad gas.

We cleaned up the bores, got new mag side pistons and put the stock heads back on. My dad is still running his - but complains about the lack of power because of the stock compression.

backcountryislife · Feb 21, 2010

it was my 09 1000, rkt 14.1:1, oil delete, SW Y, BDX intake. I run legend premixed @ 32:1 along with 1/2 gal of race gas & get my gas from the same non ethanol station every week, no variables there. I'll be tearing it down in a few hours, and we'll see what happened.

I'm leaning toward a gasket failure with some coolant ingestion, I didn't even think to look at that yesterday while on the hill. The low end bog I was getting kinda makes sense with that to me. Could the borderline temps have eaten away my head gasket little by little?

Alex, I was about 15 mi in @ spring creek (way left of where the trail meets the cornice) had to do a bunch of trail building to knock down a few feet of pow, but we got a good trail built & two doos pulled the sled out on an equalizer setup. It actually went pretty smooth.

The last 3 rides have been tough, another snapped steering post, broken helix, burned motor. crap.

AaronBND · Feb 21, 2010

Sorry about all the trouble. Just use it as an excuse to make it better, faster and more reliable! Good luck and let us know..........

Aaron

backcountryislife · Feb 21, 2010

the only better/faster I'll be doing would be to turbo it!!! I just want it back to totally reliable.

smokindave · Feb 21, 2010

A friend of mine had his burn down last weekend for no reason,had not made any changes,after taking apart the dealer found that there was a coolant leak that caused one piston to melt down.Four corner cold seisure.Not covered by warrenty due to cylinder porting.

Qreiff · Feb 21, 2010

K --

That sucks to hear and, I too agree that you should look carefully for a coolant leak as the culprit.

Godspeed...........the deep chit has arrived!!

backcountryislife · Feb 21, 2010

Qreiff said:
Godspeed...........the deep chit has arrived!!

Yeah Q, thanks for reminding me of what great timing this is.

Qreiff · Feb 21, 2010

Really wasn't jabbin' at ya. I know how bad this sucks. Just wish you good luck.

backcountryislife · Feb 21, 2010

Qreiff said:
Really wasn't jabbin' at ya. I know how bad this sucks. Just wish you good luck.

I was just messin with you, it's just the way it goes that the season has sucked, but now that it looks to be turning I run into problems.

As long as the bottom is fine this will be an easy fix.

hatchers · Feb 21, 2010

how many miles?

you say it ran great, then burnt down, this should not be related to the fuel pump, as this fuel pump will degrade and start to loose pressure.....or this is what ive seen with a fuel pump

backcountryislife · Feb 22, 2010

About 2k miles, it had a small low end burble, kinda felt like the exhaust valves were open (felt like a delete kit, but without the gain in the middle) I haven't torn it down, but the coolant bottle is empty, and it never got hot, so I'm guessing it ate some green stuff.

sled has run perfect for 2 years, and today, went lean.(burnt down)

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