OK, I've exhausted every angle that I know. I have a 1996
Yamaha Warrior that was all stock, and ran good. Wanted a little
more performance, so I put on an FMF Megamax pipe, and installed
a K&N filter. Took it out for a spin, and it runs great on the low end,
but starts to miss (BAD!) and run rough after around 4-5000 rpm.
Feels like it is hitting a rev limiter only at half throttle.
Looked at the plug and it was a little light, and running too lean.
Pulled the stock 145 main jet and put in a 155. Still runs exactly the
same, but the plug looked better. OK, pulled the airbox lid. Same thing.
Pulled the 155 main and put in a 165 main. Still runs bad enough that
you don't even want to ride it. Dropped the needle clip one notch. Same
thing. Put it back to the center position. Plug looks beautiful now. Light
chocolate brown. Air box lid back on. Losing more hair out of my already
Pulled the carb and cleaned it (Was spotless inside). Checked float level,
which was fine. Pulled the intake while I had the carb off to check for rips
in the rubber. No leaks. Runs the same. Dumped the gas and checked for
water in the tank......Nope. Ran a compression-all was fine....
Now here's the one that sent me whimpering.......
Decided to put it all back to stock. Everything back: pipe, air cleaner, jetting,
everything. Runs just the same. Missing like crazy. Sooooo, I decided it must
be in the ignition. Changed the coil. (Had a buddies '96 warrior handy) Runs the
same. Swapped CDI's. Same thing. Even got mad enough that I pulled the stator
and swapped them. The DANG thing still won't run right!!
Does any one have any ideas?! What the heck have I overlooked? I have been
fooling with atv/motorcycle, boat, car and snowmobile motors for the better part
of 25 years, and this one has me completely baffled......Any ideas would be greatly