Engine not running right, I'm stumped
 

I've got a 1999 Explorer 400 4x4, it's got a 2-stroke engine and I can't get it running right for the life of me and deer season is coming up! Here's my problem: The engine feels like it has no power, in nuetral it will not rev up all the way, maybe only 1/2 - 2/3 of the way, when in drive it has no power past like 20mph, it just won't go, it sounds like it wants to go faster but the engine just won't let it rev up much at all, the throttle also sometimes feels non-responsive. Any ideas on what might be my problem would be greatly appreciated, thanks so much.

Engine not running right, I'm stumped
 

I have two things that come to mind and both are carb/fuel related. The first is water in the fuel. The second is a clogged main jet. I would remove the float bowl to check for both possible problems at the same time. If there is water in the bowl, pour it out, drain your tank, slap it back together, add new gas and give it a try. No water in the fuel? Remove the main jet and make sure it is clear.

Give that a try. If that's not the problem nothing is lost but time. Oh yeah just a reminder don't forget to turn the fuel off before removing the bowl.

GOOD LUCK on the quad and the hunt[img]i/expressions/face-icon-small-happy.gif[/img]

Engine not running right, I'm stumped
 

One other thing to check is the muffler, yours is fairly new, but I have seen some factory 2 stroke silencers that got all plugged up with half burned oil and crud from not being driven hard once in a while to burn out the deposites in the baffles. Take it off and take it to a dealer to inspect,or try to take an air hose and blow it out ,see if it seems restricted. The syptoms you describe sound just like a buddy of mine who had an old 250 trail boss, silencer was almost plugged solid, he rodded it out, and knocked chunks of black crud out, ran like a new one after that.

Engine not running right, I'm stumped
 

Never hurts to do a compression check.... ok, sometimes it does