This sled is the worst thing you could ever buy, I bought one back in2007 and I had it part of the winter! The jeting was so pickey becuase it was a so called a "race sled". Dont get this sled messed up with a xcr or the legendary xc, the xcf has a 440 fan by fugi. the problem was that it would only run good at zero degress for about 5 miles then it would just dog down and then blaaaaaaaa..... I would shut it off then start it back up and it would run just fine for about another mile, it would drive me mad! my buddie had 02' indy 500 he would be drift busting well i wait 5 minutes for the pice of crap motor to cool down. I have heard that they only made a few of these and they all have the same problem! So if you see this sled with low miles dont be suprised! Dont bother with it! this sled has no fix!
I forgot to include that this problem occures with any of polaris 440 fan motors around 91' becuase of the clutch that revs to about 5000 rpms and it gets stuck in some gears and does not have enough power to pull its self unless you feather the throttle to knock its self out of it or just shut it off.
Check your fuel system - that can cause bogs as well. Two possibilities come to mind immediately:
1) Could have a plugged fuel filter/pickup. I have had problems like this - sled runs ok for a while then filter or pickup clogs. Shut it off for a little bit and sediments settle enough to run again for a short while.
2) Vapor lock in the tank. Make sure the vent is clear - if the fuel leaving the tank isn't replaced by air it gets harder and harder to pull fuel out and it bogs. Let it sit for a little and enough air leaks into the tank that you are good for a while again. If this is the problem you should be able to open the fuel cap (when bogging) and hear a 'whoosh' as the air rushes in.
Other possibilities - sometimes coils or connections can be temp dependent. If you have a coil going bad it is possible when it warms up it doesn't produce enough voltage any more. You should be able to find/get the way to test coils for your sled (sorry I don't know particulars on yours) - usually it is measuring resistance values from connections to the coils. Test them cold then test them hot when bogging down.
Check the compression hot and cold as well - may have something going on there.
Even with a free-air engine it should not be overheating in 5 min at 0F. Something else is going on...
Waiting for snow again...
Last edited by dlaine; 07-26-2012 at 09:15 AM.
Reason: Had another thought...