correct jetting 03 yz 125

[ukracer]

just been reading some of the posts about problems with 03 yz 125 please could you give me some useful information on how to know if bikes is running properly and signs to look out for to prevent any possible problems what fuel/mixture etc would be gratefully appreciated
Cheers

 

[antont]

Absolute stock jetting. Do not increase compression, do not run aftermarket base gaskets that are thinner, do not advance timing, run highest pump octane and all will be well
Regards
Anton

 

[ukracer]

thanks anton

 

[Danny23]

My 03 YZ125 was a bit rich from the dealer. I went through a crap load of plugs before I dropped the pilot to a 37.5 (from the stock 40), and raised the clip one position. I live in Cincinnati, Ohio (not sure what the elevation is), and this jetting is spot on for me.