2003 Yamaha YZ 125 "jet pilot" Questions

what is the size of main jet of YZ125? Main Jet: 410 Main Air Jet: 2.5 Jet Needle: 6BFY43-74 Needle Jet: S-1 Pilot Air Jet 1: #40 Pilot Outlet: 0.7 Pilot Jet: 40

pilot air jet 1 and pilot jet 2 http://www.cmsnl.com/yamaha-yz125r-2003_model11245/partslist/A-12.html Site above has all the parts and specs for your bike. Jet ranges are large for a YZ as many mod's

jet needle (unlike other Yamaha's) the bike's factory jetting is 45 pilot, NBKF needle on the 2nd clip from the top, and 138 main. This bike tends to run a little rich off the bottom, so I'd recommend

...pilot jet now with std main jet. Took out the 40 pilot jet because of breaking up at low cruising speeds. this will depend on what gas oil mixture you have check this topic out. ...

...pilot/slow jet. 2. 1/8 to 1/4 throttle is managed by the air-screw, pilot/slow jet, and throttle slide. 3. 1/4 to 1/2 throttle is managed by the throttle slide and jet needle. 4. 1/2 to 3/4 throttle ...

...pilot jet - it won't increase the maximum volume through the jet. Adjusting the needle is a fine tuning thing - mainly for the mid range. Change the pilot jet and main jet. Go to your local shop ...

jet and pilot jet numbers found stamped on the jets and needle number. You don't say where it is you are trying to get power. 125s have poor bottom mid power, it is all on top for racing. Don't change

pilot cicuit, from there you transition to the needle jet/and jet needle. That controls the 1/4 to 3/4 throttle and then the main' jet which controls WOT. you may have a air screw that would be before

pilot jet in the carbi is blocked either way I first of all would remove the carbi and air filter and clean thoroughly, compressed air clean every thing - flush with fuel or carbi cleaner everything -