Fuel-Oil mixtures and jetting

[cr85rb_rider]

Ok the guy i bought my rm250 from jetted perfect for 50-1 mix, and he said hes usally just in the lower rpms, and im already riding pretty aggressive, so i want to start running ither 32-1 or 40-1, which one is beter for a 250?

And once i change the fuel-oil mix will i have to rejet the carb? or will it not make a differance?

 

[Moose]

32-1.

Yes.

 

[cr85rb_rider]

Thanks, so probely just a click or to richer on the air screw should do it?

 

[Moose]

I duno, the RM250 isn't here for me to check. And I have no clue about how to jet a bike. The RM250 we ride uses 32-1 and doesn't smoke at all.

 

[cr85rb_rider]

ok, thanks

Im going to mess with it tommarow after school, and see if i can jet it right

 

[dezryder]

What oil are you using? And why the ratio change? 50:1 is fine IMHO.

 

[Mully]

32-1.

Elliot may I ask as to how you have come to the conclusion this ratio is the best?? Extensive studies that you have conducted?? Years of trial and error??? Enquiring minds want to know.

Maybe a valve grind would help....................

Mully

 

[KX02]

32:1 is reccommended by the manufacturer isn't it?

 

[cr85rb_rider]

Yes, it is, it seemed to be running a tiny bit rich at 60 degress and perfect at 35-40 degrees this morning, so with 40-1, it should leanen the mixture and i think it will run better since its rich with 50-1, am i right?

 

[76GMC1500]

I have run my bike everywhere from 16:1 to 50:1, I didn't even have to touch the air screw on the carb. Even on very technical riding at 16:1, it didn't foul a plug.

 

[cr85rb_rider]

Ok thanks, ill run 40-1 for now and 32-1 later see what i like best