Need to solve a 1979 55hp Johnson fuel flow issue

H2oallyear

Recruit
Joined
Apr 6, 2014
Messages
5
I launched a new to me boat with a 1979 55 hp The motor warmed up ok. It ran ok ish. Was able to hit 34 mph. It did sound good but started acting sluggish so I headed back to the boat launch. Maybe ran 1 mile. Now it still starts and idles reasonably well but I have to play with the idle speed lever a bit to keep it running. At idle. When I drop it into gear, it dies.
It will start again ok. If I pump the bulb, which is fairly hard, then put it in gear, I can run for 50 feet or so, then it dies.

I have clean out the fuel screen, drained the carb bowls, fresh premium fuel, new plugs. To get it up to speed , I did have to feather the throttle . When she is running it does sound clean and solid. A compression test before launch was 140+ lbs.

I believe it's a fuel supply issue and was looking at what sequence I should check things out. I was able to get her up to 30 + once but that was it. Sounds good at idle!
 

kodibass

Master Chief Petty Officer
Joined
Apr 10, 2010
Messages
864
Re: Need to solve a 1979 55hp Johnson fuel flow issue

I have at least 3 of you motors, the manual states when doing the carb sin& linc that the steps one thru six must be followed in order. So that would be the first thing I would do. then see if it helps.
 

bonz_d

Vice Admiral
Joined
Apr 22, 2008
Messages
5,274
Re: Need to solve a 1979 55hp Johnson fuel flow issue

I have at least 3 of you motors, the manual states when doing the carb sin& linc that the steps one thru six must be followed in order. So that would be the first thing I would do. then see if it helps.

Hope he has a good manual or at least a good youtube video!
 

H2oallyear

Recruit
Joined
Apr 6, 2014
Messages
5
Re: Need to solve a 1979 55hp Johnson fuel flow issue

I have at least 3 of you motors, the manual states when doing the carb sin& linc that the steps one thru six must be followed in order. So that would be the first thing I would do. then see if it helps.

Sorry, not sure what you mean. I don't have the service manual but getting one is probably a good place to start
 

bonz_d

Vice Admiral
Joined
Apr 22, 2008
Messages
5,274
Re: Need to solve a 1979 55hp Johnson fuel flow issue

Again my recommendation is ebay. I've had very good luck finding them there used and in VG condition.
 
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