boggs at low rpm

[diew]

Have a 1993 yz250... It boggs at low rpm then suddenly hits the power band. It also easily loads up when i'm going down hills or when the motor isn't running in the power band. The stock jetting is a mikuni 350 main jet and a 50 pilot jet. I leaned out the main jet to 330, then to 320
temporarily. The bogging did get a little better but is still bad enough where its annoying. What could i do to fix this problem? Should i make the pilot jet leaner? maybe go down to a 30?

thanks..

 

[Gibby]

Try a 45 pilot jet. Put the needle clip on the 3rd position down and turn your air screw 1.5 times out from dead stop, and go from there. The 350 main is probably fine, the main jet is just for wide open throttle anyway.

 

[diew]

There is a 40 pilot jet in there right now. Should i go leaner? maybe to a 37.5 or 35 ?

 

[maddmack]

good info

If you send me your email I can send you some really good info on jeting it comes from a race man.

 

[diew]

.
my email is "diew@krupt,com" , = .

 

[maddmack]

I ll find that stuff and send it tonight some time

 

[sick 96 250]

The bog is normally a lean condition on your pilot, try going up a few sizes on the pilot instead of down, your main jst controls you open throttle, not the low rpm's. Pilot is more the low end part.

 

[maddmack]

did you receive the info?