wont stay idling

[stumbler]

I have a 76 25hp evinrude that I just put new piston and rings in it. Got it all back together and it will not idle. Starts up good. What j have done. Readjusted break points, slow idle needle, new fuel pump screen and gasket, fuel line, primer bulb, spark plugs

 

[nwcove]

Re: wont stay idling

carb synced to throttle cam? try pumping primer bulb? spark open air gap tested to 7/16?

 

[boobie]

Re: wont stay idling

If you hit the choke, what happens ??

 

[HighTrim]

Re: wont stay idling

Would it idle before? What caused you to swap piston and rings? What was the previous compression, and what is it now?

Most importantly, was anything else done other than open the powerhead?

 

[stumbler]

Re: wont stay idling

Had top piston fail. Think it got hot or wrong plugs. Dont know what the compression was before but now I have 120lbs in both cylinder. I put a new thermostat, and new water pump impeller in it as well. How do know if the carb in synic. The old plugs that were in it were a little longer but I put what the manual said. I also put in new float, high speed needle set in the carb as well as A new low speed needle bushing. Here some pics of why I need to rebuild.

 

[nwcove]

Re: wont stay idling

View attachment 217077

no way that engine will run correctly with that baby holding on to the piston!! :laugh:

 

[stumbler]

Re: wont stay idling

he's my little helper

 

[bonzoscott]

Re: wont stay idling

The round shape of the magneto plate has sort of a wing on it. That wing is a cam that contacts a roller connected to the throttle plate. As you twist the grip, it advances the the ignition and throttle at the same time. See if that roller is worn. If not, my shade tree way of giving help is put some duct tape on the edge of that cam/wing and increase the throw. See if it idles. Quick - easy but not permanent. That cam/wing is adjustable.