winter riding yz125

[uw153]

Hey guys, what jetting are you guys looking at for 600ft above sea leavel at anywhere between 15-40 degrees? I have a Vforce 3 reed setup but that's about it. Right now, even running the stock expansion chamber and silencer. My current jetting is a 42.5 pilot, 6BFY43-3 needle and 440 main. This setup worked real good at 70 degrees with it being a little rich but I was riding sand then so a little rich doesnt hurt. It seems with the Vforce3 it likes to be a little richer.

Any recomendations??

[mlatour]

What year YZ125?

 

If by chance it's a 2006-2010, the suggested 'winter / sandy conditions' settings in the service manual for below 50°F are:

 

USA :         #42.5 pilot, 43-74 needle, 4th clip position, #440 main jet

EURO :      #47.5 pilot, 43-74 needle, 4th clip position, #460 main jet

 

I think the richer EURO settings take in consideration that it may be a bit colder in that region and,

that the current longer OEM silencer was their stock silencer a few years earlier than in north america. (2011-on here)

 

If you roughly 'extrapolate' their suggestion pattern, it indicates

about a one step richer increase on all fuel circuits for approximately every 15°F drop in ambiant temperature.

 

Cold weather/winter tip: don't over-oil your air filter, it will thicken considerably and block the airflow thru the foam.

Edited November 18, 2015 by mlatour

[uw153]

Mine is an '06. Thanks for the reply. I am really wondering if anyone else runs the vforce3 what their jetting is for anywhere down in the low 20's. Its trelleborg season!!!