Hey guy's, I'm not sure as to what is going on with my 400 here is the deal.
At the ranch(6000) while training dogs the machines run's good. ( never run it higher then 15MPH) but in the hills
(12000) it starts to bog down at a 1/4 throttle (when it's warmed up) The book says to run a 175 main jet. I have went down to a 165 with no luck. I've also noticed it get's hot but does not overheat. The water in the rad. has movement, and the fan works ,so I don't think the cooling system. Does anybody out there run a 2 stroke 400
at 6-12000 feet?
one more thing that I have tried ......when it boggs down I have turned on the choke and it does help it.
( the main jet is not plugged I have checked that ) what do you guy's think ......Do I need to go up or down with the main jet? Or i'm I way off?

I've been working on this machine so much that I'm just brain dead now. Thanks for any input.

 

Drod,
sounds like you need to adjust the air/fuel mixture. Its a small brass screw on the carb to the left of the larger idle adjustmnet screw. turn it to the right until it seats then back off 1 and 1/4 turn. If that dosent help, the vaccuum hose that that is on top of the air inatke (and is supposed to be teed off with the over flow hose vent, followed by a check vent) may be clogged. I had to disconnect the intake vaccum hose from the overflow to get my 400L running right.


BTW, what is the black toggle switch on the left front (by the speedo) used for?