Crank case full of gas.. why?

[CATillak]

My cat burned down last year and when i got it back finally and took it apart the case was FULL of gas. I know the TPS went out at about the same time the pistons melted because everything went bad at once. Wire came out on the TPS* My only guess is that the needle isnt sealing in the carbs?? I dont know i need help!

01 mountain cat, 800.

Thanks

 

[joshkoltes]

needle and seat

needle isnt seating. gravity flowing gas into case. how long has the gas been in the case? if too long it probably varnished your crank bearings needing replacement.

 

[CATillak]

**** a year lol. i just had to replace the bearings because the PTO seal was leaking , probly been doing this for a while. I know it gradually got nearly impossible to start the more i rode it.. Shoulda stayed on the REV n left it on the trailer...

 

[theultrarider]

Needles and seats in the carbs....very common especially on Poo xlt's and xcr's. We used to go through a set a year on those sleds for some reason. That usaually will not make an engine burn down however! They run pig fat, if they even run at all. The other thing that can cause this is a torn diaphram in your fuel pump. The fuel will go down the impulse line that runs the fuel pump that connects to the bottom of the crankcase. When this happens, you can actually starve the carbs of fuel and lean it out,,even though you are flooding the bottom of the case. Good luck, hope this helps you.
Tim

 

[CATillak]

The night was a bad night all together. The sled was backfiring and hardly running but the EGTs were at like 900 just at idle... The sled freakd out honestly lol. After it burnd down, it got left on the trail for 3 weeks due to a rediculous cold snap and not having a hauling sled (skandic burnd down the next day) it just didnt get brought back. I noticed my TPS was broken too soo it could be many things. Iv got a new set of standard CC jugs and pistons coming so ill start trouble shooting it. How can i check the diaphram in the fuel pump Tim? My guy at Cat wants to look at the carbs so he can look at the seats. He even comes to my house to help me, good dealer ay.

Thanks guys

 

[theultrarider]

The way to truely check you diaphram is to take the fuel pump apart and look at it. But, the quick check (not always right) is to unhook the fuel lines from the carbs, and the one to the crankcase. Now try blowing into the one that would hook up to the case. YOU SHOULD NOT be able to blow through this one! If you can, your diaphram is gone. Just because you cannot, you may still have a small leak that only shows up under pressure. Most likely it is your needle and seats. Once agian, just cuz they look good to the eye, does not mean that they will hold fuel! It is the start of a new year, and sounds like a new motor for you as well, just put new needles and seats in your carbs and eliminate that issue. If you still have flooding issues, then you need to rebuild the fuel pump. That is cheap and easy as well, If it were mine and ride the remote areas that you and I do, I would just rebuild that now to start with and stay off the tow strap!

 

[CATillak]

Thanks Tim, as soon as A.S.S opens im gonna pay em a visit and see what i can pick up for a decent amount, as this is my back up sled and only gets ridden to my cabin. I still would like it too be reliable though for whom ever gets stuck riding it lol. Im probly going to need to buy new bearings again it sounds like.