1977 Johnson 55 very low power

[guido2]

This was an intermittent problem but now is continuous. Runs good but will not plane the boat. The boat is a vintage aluminum 20" transom 14' Alumacraft runabout. The switch box/module is new and the coils and stator were replaced by previous owner. Trigger unit passes the test suggested by CDI electronics. I've tried unplugging the temperature/rpm limiter at the cyl head but that doesn't help. Maybe that wire, if shorted to ground somewhere, could be the problem? Does anyone know what the impedance to ground should be for this wire? The fuel pump has been replaced and carbs were very carefully cleaned, including running a proper size drill bit by hand through the main jets. Any techs out there to help? Thanks, Guido

 

[racerone]

What are the results of a compression test ??------That is the first step in trouble shooting an outboard motor.

 

[eclark53520]

+1 to the compression test, let us know what each cylinder's numbers are, also use an air gap spark tester set to about 7/16th's inch. If you don't have a bright blue snap of a spark, you need to troubleshoot your ignition system.

 

[guido2]

I agree, my compression gauge never collects any dust. Its 115 and 118 psi. The motor has a factory replacement powerhead with about 50 hours on it
I have been a professional outboard repairman since 1967. I was trained on the job at two separate shops in Duluth MN. In 1974 I built my own shop in Duluth and still operating today. I have about 150 complete outboards and a 56 by 90' storage shed. My wife builds race engines for Wissota dirt tracks, she is from the Philippines. I also rebuild great lakes ore carrier engines specializing in Colt-Pielsticks. This is a part time job with Lindholmen Engineering Company out of Jacksonville FL. These engines develop 8000 hp at 420 rpm and with a displacement of nearly 60,000 cubic inches. 2 of them drive a 1000' ore carrier moving 55,000 tons of taconite pellets. A typical overhaul on a CP will cost about $500,000 and an engine replacement about $10,000,000.

 

[racerone]

Should be no problem trouble shooting a simple 55 HP outboard motor I would say.

 

[guido2]

Hah! You too are stumped, eh?

 

[racerone]

If the motor was on my work bench it would take just minutes to figure out where the problem is.

 

[guido2]

Fine then I'll figure it out myself, this is my last post on marineengine. I'm not interested in answers from some smartass!