1978 Johnson Seahorse V4 (85ML78C) Engine Runs Away

[seph2004]

I have a 1978 Johnson Seahorse V4 85ML78C, and I replaced the fuel pump and spark plugs. I was able to get the engine started, the choke solenoid is working properly by pushing in the key, but it won't start when I use the key-in choke. If I put the manual choke on, pull up the warm-up lever and start it, it will run, then I push the warm-up lever down and manually take the choke off and the engine won't idle, it tries to run away.

I took the carbs off and I am going to go through them, but is this a situation where I would need the engine evaluated further? Maybe something is wrong with the piston rings for them to have excess oil blow-by? Anything else I can try? I don't want to run the engine for too long at the RPMs it tries to run at.

 

[racerone]

I do not believe you have to worry about ---" oil blow-by"-----On this 2 stroke motor.-----Post the compression test numbers.

 

[F_R]

Could be the remote control cables adjustments?? Try disconnecting the cables from the motor and see it can be set to idle without them. If it will, then reinstall the cables and adjust them to fit the motor. Never adjust the motor to fit the cables.

It ain't oil blow-by as you suggested. Two-strokes don't work that way.

There are 3 positions for the manual choke; choke-off, automatic, and choke-on. Has to be in automatic for the key choke to work.

 

[seph2004]

I think I resolved the issue. The idle screw was pushed in pretty far and it was keeping the high jets open too much. I backed out the idle screw a bit and tried firing up the engine without the throttle cables and the engine isn't racing up anymore. I am going to fiddle with it tomorrow a bit put the cables on and test it more.

 

[Johnm329]

Did this work for you? I have same issue on a 1974 Evinrude 115493B, want to run away. No idle.