Johnson 85 will not Idle

I have a 1974, 85 hp Johnson outboard that I canít seem to get to idle. It will run a few seconds and die, sometimes longer. It also will cut out occasionally at higher rpms, but not too noticeable. I have completely rebuilt both carbs, all the electrical, even tore down the power head and replaced all the gaskets and seals. I checked the reed block assembly, replaced the fuel pump, changed coils, spark plugs. During the tear down I found
the lower crank bearing was bad and replaced it. I also inspected the seal rings on the crank and found them ok. I ran a compression check on each cylinder and found them
all equal, I donít recall the readings. If anybody can help me turn over a stone that I havenít thought of, I would appreciate it. 

Thanks

 

Since you checked almost everything possible, I would look at the power pack. It is possible you have a cylinder or two being dropped. It is the only thing you did not list.

Randy

 

 

Please submit whatever questions you have to IHRTechTalk@yahoo.com.  All questions and answers selected will be displayed on this page as they come in.  Note: though all boaters are welcome, priority may be given to I.H.R. members.  Randy can not be held responsible for any advice given.  Though his information and expertise is second to none, he has no control over what you do with your boat.  It is up to you to boat safely and act responsibly, and his advice is only to be used as a guidance for your high performance boat/motor of which you are the one responsible for the risks involved.

Thanks,
Mark C.

 

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