Need jetting help

[theblasterboy]

Ok so why I have my bike tore down I was in need of jetting help.
My bike runs fine until about 3/4 throttle then it bogs to a stall. It has a FMF fatty with pore core 2 shortty silencer and a prox piston in it. It was rebuilt about 10 hours ago on piston. No other thing has been done to the motor. Also I've tried running50:1 and am at 40:1. Any help is needed ASAP plz so I can get the parts order ASAP.

 

[UncagedShadow]

i would run regular 32:1 premix ratio. Now for that fmf pipe, i beleive it should be between 270 and 290 maybe 300. In that range should be good with the airbox lid off.

 

[theblasterboy]

The seat is the airbox lid lol it get hot in the summer in my area
so I tend to run it a lil rich

 

[Larry's Shee]

Have you cleaned the carb and filter? Fuel petcock and tank? Have you done a plug chop? What does plug look like? Tried a new plug?

BTW guys, he's asking about the YZ

 

[theblasterboy]

yea its got a brand new plug really what im asking is what jets i should be using

 

[Luni]

Per FMF they recommend as a starting point,

Main: 350-360
Pilot: 50-55
Needle Clip: 3rd position

Basically this is a stock set up or a little richer than stock. Remember other modifications such as reeds could offset these.

You are going to need to pull your carb apart and verify what jetting you already have though man.

 

[theblasterboy]

Ok so today I ordered a 320,330,and a 340 size
Jets. The one currently in the carb is a 350. This should leannit out
With playing with the air screw hopefully and fix my bog problem. Thanks for the tips guys.