Super M surges

Chester5731 · Apr 21, 2014

My Super M sat for over a year without running. After I put some bearings in the trans I had trouble keeping it running. It would run at high speed but not idle. I took the carb off and cleaned all of the passages, set the float, put a new needle and seat in and even had the manifold resurfaces and put in a new gasket. When I first put it together it ran fine. Last week when I used it to pull some logs it started surging at idle. It ran ok with the idle screw in all the way. I had it running yesterday and it started surging no matter what I did. At about half throttle it will smooth out and run fine. Any suggestions?

David G · Apr 21, 2014

Idle circuit plugged, I think the mixture screw is an air bleed.

used red MN · Apr 21, 2014

(quoted from post at 14:28:15 04/21/14) My Super M sat for over a year without running. After I put some bearings in the trans I had trouble keeping it running. It would run at high speed but not idle. I took the carb off and cleaned all of the passages, set the float, put a new needle and seat in and even had the manifold resurfaces and put in a new gasket. When I first put it together it ran fine. Last week when I used it to pull some logs it started surging at idle. It ran ok with the idle screw in all the way. I had it running yesterday and it started surging no matter what I did. At about half throttle it will smooth out and run fine. Any suggestions?

Since you have just cleaned the carb here is a trick you may want to try. (or not) An old school auto mech taught me this. Cross two plug wires (ie put the # 2 wire on 3 plug and 3 on 2) start it up and open the throttle up quickly to cause it to backfire into the intake, repeat several times. This occasionally will blow out whatever is in the idle circuit and allow it to run acceptably again.

Super M surges

Chester5731

Member

David G

Well-known Member

used red MN

Well-known Member

Similar threads