1976 85 hp johnson

borz80

Seaman Apprentice
Joined
Jun 25, 2008
Messages
32
I have a 1976 85 hp johnson and it has been running real rough lately. I had it out last night and i could barely get the motor to run in forward. I finally got it to move but it was only going about a quarter of the top speed and wouldnt plane out. I adjusted the throttle cable and i realized that wasnt the problem. I then adjusted the lever connected to the throttle i tried to loosen the plastic clip then put it back on. This adjusted the little roundish piece that says start on it. This made it worse. It also sounded like it was only picking up 2 cylinders . I got the boat out of the water and checked my spark and realized that all plugs were giving a blue spark but one. This one one was only giving a pink spark. Im not sure if that was the problem.
 

crb478

Lieutenant Junior Grade
Joined
Dec 6, 2006
Messages
1,036
Re: 1976 85 hp johnson

The weak spark on the one cylinder could be the problem or part of it anyway. First take the plugs out and check the compresson and make sure that all the cylinders are within 10 percent of each other and hopefully over 100psi. If they are try switching coils with the weak one and see if the weak spark follows the coil. If it does replace that coil. If not it may be the power pack so more testing will be needed.
 

borz80

Seaman Apprentice
Joined
Jun 25, 2008
Messages
32
Re: 1976 85 hp johnson

i replaced the plugs and it seems that it is burning blue now. I am going to keep watching it and i hope to put it in the water tomorrow to see how it runs...if it still runs poorly im going to change the coil. Thank you for your help.
 
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