1998 YZ125 running lean

What would you guys reccomend for jetting settlings on my YZ125? it has a fmf exhaust system and Vforce Delta reeds installed. my altitude is at 2021 feet. I am at a loss as to what jetting settings would work for me as Ive never really jetted a bike like this before. Its running extremely lean, it even smells like its burning away inside, its jetted for 0 altitude as it was bought out of california. there is a dead spot in the throttle at about 1/4 turn where it just splutters and cuts out.


Help would be very much appreciated, thankyou

Whats your current main jet, pilot and needle setting?

Whats your current main jet, pilot and needle setting?


whatever the jetting settings FMF reccomended, thats what the guy i bought it from told me.

At what rpm is it running lean?

At what rpm is it running lean?


at about 1/4 of the throttle twist. not sure what RPM that converts to.

We also found that the powervalve governor has snapped, which adds to why it is lacking top end power. still runs extremely lean at 1/4 throttle however. 

The go up 2 or 4 on the pilot jet it could s

Also be your pilot screw

As the original one said, but I think he meant air screw. If your out less than 1 turn on the air screw and running lean go up 1 or 2 sizes on the pilot. If out more than 3 1-2 turns time for smaller pilot. I'm working 3 things right now, so I might have that backwards. I do know that you DO NOT want to keep running lean. Better a little rich than lean. Lean mean hot, melted and $$$$

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