Logo
FULL SITE MENU

rough idle

G

Glenn Loyd

New member
Hello fellas, I have a 1975 25 hp Johnson I have a few issues with ..when it idles it misses...its a hard miss that jerks the motor then it dies.. it almost seems like its trying to run backwards....it does it only at idle...any ideas? thanks for any help.
 
when was the last time the carbs were cleaned and adjusted? sounds like one of the carbs is out of adjustment.
 
There's only one carb. Does it straighten up for a few seconds when you choke it? If so its running lean at idle, back off the idle mixture screw a bit.

If it is electric start look to see if all ground wires are clean and tight and check for a melted rectifier. Might try running it at night or during low light to see if any of the wires or coils are arching. If all seems cool there overhaul the carb and fuel pump.
 
the carb was rebuilt over the winter and adjusted by the book...it does not have electric starter (wish it did) could the fuel pump cause this..ive been suspecting it was bad or going bad because i've been having trouble with the priming bulb..ie taking a log time to get hard and losing prime..
 
Back
Top