Jd crawler40

kevencyr · Post by **kevencyr** » Sun Sep 06, 2015 9:04 am

Got this 40, was working really good until one day started to backfire out the carberator air intake. Timing check, carb check, everything looks ok, any advise on what could be wrong. Thanks

DukeofDeere · Post by **DukeofDeere** » Sun Sep 06, 2015 9:25 am

Sounds like a sticky valve.

Duke

rustywheel · Post by **rustywheel** » Sun Sep 06, 2015 9:36 am

In order to backfire thru the carb, the combustion fire must get past the intake valve. May be sticking but most likely a piece of the valve burnt away or a piece of carbon lodged on the valve seat holding it open.

boler76 · Post by **boler76** » Sun Sep 06, 2015 5:46 pm

My 40c did exactly the same thing and what I found was that the pivot pin on points was sticking and some times points wouldnt operate and when they did it would backfire, this was an intermittent problem not continuous

kevencyr · Post by **kevencyr** » Fri Sep 11, 2015 2:32 pm

we did removed the cylinder head, all valve inspected, nothing wrong was found. reinstalled cylinder head and adjust valve gap. its doing the same thing as before, backfire from carburetor. don't know what to do next, going to change the condenser and point i guess. any idea someone.

gregjo1948 · Post by **gregjo1948** » Sat Sep 12, 2015 3:47 am

Check valve timing and, as boler76 suggested, check the points for proper operation and also check the distributor bushing for excess wear causing the point gap to be erratic. gregjo1948

JDcrawlers Messageboard

Jd crawler40

Jd crawler40

40c backfire

Who is online