I have a 1993 Yamaha 350 warrior and am having problems jetting my quad for 4000 feet above sea level. The stock specs at sea level call for a 150 - 152 main jet. I upgraded to an FMF exauhst and K&N air filter. If anyone can shed some light on the situation please let me know. Thanks for the help
Bryan Hope

 

one method thoue probably not the fastest is to use the sparkplug to gauge by drive in speed range the jet your trying to figure then sut it off check the plug if its lean go the next size rich and vise versa