I just got an 86 250r but is running veary fat. It had a 150 main jet so i keep gong down till it is running good, but that was all the way down to a 118. I know stock is around a 148. The atc has a FMF pipe FMF reads (new) stock cage and a reed spacer. I donot know anythig about the bore thow. With a 118 it runs good not to lean been doing plug checks. So last light i took the carb off to see of I could see anythig wrong with it and there was nothing. I pulled it all a part sprayed brake cleaner therow all the holes no holes where pluged up. But I still want to get a new carb should I go back with the PJ and if so what MM or should i change? and what MM. Thanks for your help

 

As for your smaller main jet, it could be due to your altitude. Air thickness has a lot to do with your jetting.

 

i went from a 39mm to a 36mm and improved the bottom end a lot!!!!!!!!

 

this may sound weird but one time i over oiled my air cleaner and it did the same thing becuase the oil went to the motor and ran rich. also you could have a air leak like a base gasket head gasket reed gasket or carb boot. if you have a air leak it wiil run rich. 118 is way way to lean. be carful.,

 

hey its acually if you have an air leak the motor will run lean not rich, because there is now alot of air and little gas. no biggie thow, you probly just typed it to fast lol

Anyways my 86 with pipe, 35mm carb, is down to a 130, so dont feel left out.

 

thanks for the help I orderd a 35mm PWK lastnight

 

oh yea sorry bout that>[img]i/expressions/face-icon-small-blush.gif[/img]