1978 KTM 250 - Carb Adjustment

[Nick]

Do any Pittsburgh area POGGERS know the approximate number of turns for the air screw and throttle stop screw for the Bing 36 carb to get me in the ball park?  Right now, it's revving to the moon (I don't think there's an air leak anywhere).  Thanks.

[Larry Perkins]

I am not from Pittsburgh but one and a quarter-one and a half should be close.  Make sure the idle screw is not in too far and holding the slide up or that the slide is sticking for whatever reason also via slide or cable.  If all those things prove to be okay go for the airleak search.

Larry P

[joe novak]

I suggest that you remove the air cleaner and feel in the opening, or remove the entire carb, and visually inspect the carb for proper opening and closing using the throttle.  I suggest you back the idle screw all the way out, and be sure the slide is bottoming out in the carb.  Always rev the engine slightly to move the slide off the idle adjustment screw when adjusting the idle screw IN so that you do not burr the slide.   Be sure the slide groove is installed in the slide detent correctly.  Let us know if you need more suggestions.  Good luck.

[garrettccovington]

My 79 KTM has a 38mm type 54 Bing and the manual says Pilot Air screw 1 turn out.  I've cleaned the carb a bunch, but it seems like I have to turn the Idle screw in just about all the way in for it to Idle.  I've cleaned out all the little holes and everything.  It seems to run pretty good now.

I did have 1 problem, when it was reving out.  I put the cap on 180 degree''s wrong.  NOW that caused all sorts of problems with a run away motor and took me a while to figure that one out.

G

72 six-day
79 KTM MC80 250

[Nick]

Thanks guys - a lot of good information here.