06 yz 125 advice

Create New Tag

3/12/2015 5:11 PM

Just had the motor ported for race fuel, new piston and rings. Bottom was done last winter. It fired rite up but was running rich and loading up. Didnt want to rev it to clean it out cause of the fresh motor. Shut it down to adjust idle screw and wont start. Cleaned the plug it looked wet, still wont fire up. This is prob a jetting issue? Any advice would be great.


3/12/2015 6:57 PM

Try adjusting the air screw, on the side of the carb. Counter-clock wise is leaner, clock-wise is richer. Sounds like you need to lean it out a bit


3/12/2015 7:43 PM

Probably fouled the plug is the reason it won't fire back up... replace it.
Try dropping the needle and/or main jet also.


3/12/2015 8:18 PM

One thing at a time.

1. new plug, clean air filter and fresh race gas

2. then jetting.


3/13/2015 3:37 AM

Thanks guys, it has a fresh filter and gas, going to pick up a new plug and mess with the air screw. I rebuild the carb to so im hoping its the air screw


3/13/2015 4:44 PM

Start by turning the airscrew all the way in, then back it out 1.5 turns. (360 degrees, then 180 more.) You should be in the ballpark right there - at least close enough that the bike will run. (I think it should run even with the airscrew completely wrong, so you may have another problem.) The airscrew is really only effective for 2 full turns, then it's not doing anything.


Braaapin' aint easy.