Backfire

[littleokies]

1987 ezgo marathon backfires thru the muffler what do I need to fix this problem

[Dabble Inn]

Most common reason is the throttle butterfly in the carb isn't closed completely BEFORE the ignition is cut-off by the micro switch when letting off the gas pedal, Hope that made sense lol....

To put it another way,
IF the butterfly is still open a bit when letting off the gas pedal the ignition cuts off but the engine makes a few more rev's before it stops and with the throttle open it allows fuel into the cylinder without spark. Then when pushing on the gas pedal to start again it immediately ignites that raw un-burned fuel that's trapped in there, Resulting in a backfire. It could actually blow out the crankcase seals if not corrected....

The usual fix is to adjust the throttle cable so as it completely closes the butterfly before the micro switch cuts the ignition when letting off the gas pedal, I don't remember if an 87 has the built-in spring at the throttle cable mounting bracket or not. (I know an 88 does but my 85 does not) IF it does then adjust it there, IF not the most common fix is to simply add a spring from a ball point pen between the throttle lever at the carb and the cable stop behind it....

Here's a pic of mine that might help my poor explanations this morning

[littleokies]

ok thank you

[littleokies]

There is two cable one is for the throttle what is the other

[trig123]

Governor cable

[Dabble Inn]

I think an 87 had the oil injection system?? If so then that second cable could be for that, If it's not then yes it would be the gov.