[Dunkmaster]

I bought an 01 MXZ 800 this year. I rode it around the Irons area the last five days and clocked 700 miles. I thought I felt the sled perk up a bit at 450 miles. I wouldn't say that it was a dramatic change once the chip was burned in. However, it seems like the sled is running rich in the midrange (4000-5200 rpms). In this speed range the engine seems to load up and diesel a bit. Once the rpms are raised above 5200 it seems to run alright. Is anyone else experiencing this?

The plugs are as black as the seat! I have the stock 500 mains and 1 1/4 turns out on the pilot screw. I even tried removing the shims on the needles but it didn't change much. I am currently getting 10 (sometimes 11) mpg.  

I rode with someone who had an 02 MXZ 800 and he was getting around 13 mpg after he had the dealer fix it for poor mileage. He indicated the dealer changed the needles but didn't have any details. It ran a lot better in the midrange than my 01.  

 

[POWERHAULIC]

turn the fuel screws in to 1 turn & try it, it should fix the low speed burble.

 

[Dave63]

Dunkmaster - Could you find out what the dealer did?  I'm only getting 5 miles to the gallon with my 02 800.  I would really like to know how the dealer straightened out your friend's sled.  Thanks.

 

[bobber]

I too have a 800X that is runing rich in the midrange. The machine has less than 300kms on it but checked plugs at various rpm's and found them to be rich(dark brown/black). It burbbles at 1/4 to 1/2 throttle after a few minutes riding. Checked the plugs and found the PTO to be saturated. It pulls hard and even if machine is burbbling, hold throttle wide open and it seems to clear up. Is this what your's is doing? I don't know my mpg's but they must be close to yours. Dealer telling me its the carbs but I'm not buying it. I think it is electrical. Both carbs are jetted the same. Carbs are "stupid" they just deliver fuel. The ignition controls how it gets burnt. And if it where carburation, why only one? After reading posts I think Ski-Doo has a problem with the 800's.

 

[speed is everything]

dunkmaster if this is a stock sled the 500s are a little rich try 490s or 480s,just make sure you check the plugs to be sure.as far as the shim i would put it back,i have heard of doing that on the 02 but not the 01.if that doesnt clear it up turn your fuel mixture screw in a 1/4 turn as a last rusult.happy sleddin