2001 ski doo MXZx 800 carb ?

[matman]

The sled idle hangs up when trail riding and after slowing down at about 3000 rpm. At cold startup idles fine and choke all work fine. As sled warms up drops right to idle. Go riding
then it acts up. I flip the choke and then it drops to where it should be. Your ideas, thoughts, or a cure would be helpful. Thanks Matman

 

[snoluver1]

Sounds a lot like bad crank seals by what your describing. I would also check the carb boots very closely for cracks/delamination.

 

[towtruck]

Sounds a lot like bad crank seals by what your describing. I would also check the carb boots very closely for cracks/delamination.

I am having the same prob with doo 04 800 summit- boots and crank seal replaced 3 years ago - dealer says needs new reeds -local shop says carb slides are sticking at the bottom and need to be replaced-
how do you check for a crank seal air leak?

 

[snoluver1]

The "right" way would be to pressure test the engine. If you don't have a pressure tester, you can spray some carb clean or starting fluid around the seal area with the engine running. If you hear the idle change at all, the seal is leaking. Problem is its difficult or sometimes impossible to get to the mag side seal when doing it that way. Sometimes you can see oily residue around the stator area if the mag side is leaking.

 

[matman]

Sounds a lot like bad crank seals by what your describing. I would also check the carb boots very closely for cracks/delamination.

Thanks snoluver1. End of last season I did new boots and reeds and it ran like new again, just has the higher idle while riding and warmed up.

 

[snowbuff]

I had the exact same sled, with the exact same problem. Nothing to really worry about. (On mine) the idle adjusting screw wore a notch on the idle stop arm, and it would catch there when warm. Very tough to dial in to a "sweet spot". I even filed the stop smooth and that helped until it wore again. I just ended up dealing with it and flipping the choke.

 

[xyooper]

Do a compression test. I had an 04 summit 800 doing the same thing a couple years back. Did pistons and rings the following season as maintainance and found a piston that was bad. I never did a compression test before I tore it down but I'm sure it wouldn't have passed. Its a quick and easy test and might save you some $. Crankcases dont like pistons coming over to visit. Hope this helps,

 

[matman]

Thanks snowbuff and xyooper. I hadn't thought to look closer at the idle stop arm.
matman