Honda ATV Forum banner

300ex jetting problem/questions

5776 Views 20 Replies 4 Participants Last post by  Billy250X
I got a 1996 300ex with a k&n w/ outerware and removed airbox lid and a hmf slip on with stock head pipe. Really no other performance mods but i got a 40 pilot with a 130 main in it does that sound correct? Cuz i tryed 2 do a spark plug check but its freezing cold here and almost 2 feet of snow on the ground. The new plug i put in came out still shiny and looked new still. Shouldnt it have come out like a brown color?
1 - 4 of 21 Posts
Agree^^^^ you need to get it real hot about 20 min of good riding. then on the last run wind it out through the gears and shut it down in 5th like Red said, make sure you don't pull in the clutch either just let it die off.
Im running a 134 main and a 42 slow jet with no box lid.. try putting your lid back on and see if you get a different reading. running it too lean is very bad for your engine, you run the risk if melting a piston.
I would just stick the lid back on that should solve your lean issue or drop back to the stock 38 slow jet and see if it richens up. but Red is correct about jetting for the climatic changes from summer to winter. Stock engine do not need this I would also turn in the pilot screw about 1/4 to 1/2 turn and reset the idle and see how it does before ripping off the carb.
134 and a 40 pilot is a bit much drop down on the jets after you try what i told you in yourom.
1 - 4 of 21 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.