I have 2 02 MXZ 800's question is when I run them both side by side one of them seems to run flat in the midrange and top end the other sled just pulls away from it and they are the same sleds have went through the sled and can not find anything wrong . I have been told to look at the MPEM this person said that it could be altering my timing curve or the MPEM could be screwed up would this cause this effect ? the only factor I have to point this to is I rode one day( on the sled that looses power in the mid and top ) with the air box sensor not plugged in silly me could this have caused the MPEM to go into a certain mode and remain there no matter if this sensor was plugged back in or not ?
02-14-2003, 01:29 PM
I'm not sure but i've been strugling w/ a 02 x 800 for about three weeks now and can't figure it out, goes good to 80 and thats it. i'll mess w/ it more this weekend, but this one is puzzling . I first thought it was in the clutching , but I finally put my clutches on and it was better but not by much.if I find it I'll email you.
02-14-2003, 04:14 PM
Try disconnecting the MPEM module for a few minutes then reconnect it if this dosen't clear any resident TFC (trouble fault codes) you will need to visit your friendly neibourhood Doo dealer to diagnose. Assure you have good fuel (no signs of water). Check spark plug colour By warming up machine for 5-10 Kilos/Miles then installing new plugs. Make a full speed run for about 1 kilo / Half mile(listening for signs of detonation), shut down motor with your thumb still at WOT (wide open throttle), coast to a stop and check colour of the insulators. They should be a medium tan colour and the ground electrode should be silver from the tip to the bend. Also look into the sparkplug holes with a flashlight. The pistons should be dark tan at the rear (of motor) and lighter towards the exhaust port(RAVE). If this falls true your timing and fuel system aren't the problem. I have seen glazed drive belts cause the same problem. Check your max RPM at speed. If your machine over revs the drive belt is toast. If it dosen't build RPMs at the top look at your driven clutch.
I have checked all these features as in plugs wash ..etc...... everything checks out but I am leaning towards the MPEM making my problem
02-14-2003, 05:11 PM
So your wifes sled is now beating yours? I'll be ordering some clutch stuff next week. Gonna get the proper tools and try to do it myself. Might give ya a buzz for some help if i get in trouble. Also gonna be regearing too. My sled is running pretty good and the more i hear the new can the more i like it :D when we gonna ride again? Alan