Not sure what to do next - 55HP Johnson problems

nopocustoms

Recruit
Joined
Apr 28, 2011
Messages
4
Here is the short story, bought a 1970 Seaswirl Ranger 4 years ago, has a 1977 Johnson 55HP Sea-King 55EL77D motor.

It has always run and started, but would sometimes die upon going into gear, and didn't like to idle in gear it would jump around a and die often. I did the usual compression test, (140 / 144) new plugs, new fuel filter, and it worked OK, but never great. - the ball never really got hard on the big motor - replaced bulb looked for air/fuel leaks none. No change in the ball hardness.

A year ago I put in a bow tank, and everything seemed to work the same. Fastforward 10 fishing trips, it started getting harder to start - too longer to warm up and seemed to have less power. I found a leaky fuel line under the hood, so I replaced all the rubber lines, new bulb (again) did the plugs. It went back to normal (normal being poor idle intermittantly, dying when engaing in gear a few times)

Last fishing trip It was way down on power, I was at plane and it died when I slowed down. It didn't want to restart, so we just started trolling where she died - after limiting out for the day, the big motor did restart but died upon placing it in gear so we just crusied back on the trolling motor. (less than a mile to the dock).

So I decided to dig into the motor - and make it work great not just marginally.
Here is what I have done so far:
New starter (needed on anyhow)
All new fuel lines again
New bulb again
New plugs
Rebuilt fuel pump
Tore Carbs apart - very clean inside, no grit funk or nastyness present
Read through the linkage and synchronization process - everything appears to be spot on.

Here are some of the symptoms it has always had, that didn't seem to change:

Dies when you put it in gear sometimes, doesn't like to idle.
Non-smooth transition in power when you accelerate (think WHOMP sputter WHOOOOMP)
Air cleaner housing drips fuel on occasion from the front

Finally when I put it all back together, pumped the ball (still not getting very hard) and pulled the upper carb drain screw, a little gas came out - subsequent sqeezing of the ball didn't make any more come out??

So I think I may be dealing with a dirty or sticky needle and seat (they looked great?) I think I will get a carb kit and replace them, set float hieght and try it

Thoughts???
 

jmeny

Seaman
Joined
Sep 11, 2007
Messages
72
Re: Not sure what to do next - 55HP Johnson problems

I had a very similar problem to the one yours is having and it had carbs rebuilt last season. I adjusted the idle speed screw and the low speed air/fuel mix needle (counterclockwise) and it made a world of difference. I don't know if it'll be that simple on yours, but you may want to give it a shot.
 

oldcatamount

Lieutenant Commander
Joined
Apr 4, 2010
Messages
1,740
Re: Not sure what to do next - 55HP Johnson problems

You've got a blockage for sure. When you removed the drain plug and then squeezed the primer bulb, fuel should have blasted out of the drain hole. When you take out the float valve (and seat), take a very fine wire and work it through the opening, or, use compressed air to blow through it. The float height is very important, hold the carb body upside down and be sure the float is parrallel with the surface of the body.
 

nopocustoms

Recruit
Joined
Apr 28, 2011
Messages
4
Re: Not sure what to do next - 55HP Johnson problems

Ok,

So today I rebuilt the carbs - sort of, I didn't break into the soft plugs, even though it came with new ones, Seemed out of my leauge.

I set the floats and followed the synch process to a T - again sort of!

To get the idle to 750 in gear in water (big old garbage can) I had to take the timing to 9 BTDC, which is past the idle max?

Either way, it now idles fine in gear in the water, and seems to run a little rough at idle - the thing is it idles at almost 1100 in nuetral...

The needle and seats were most likely the culprit, the ball is now hard - and I was overall impressed with the way it worked tonight - but I am not 100% HAPPY
 

Big flop

Petty Officer 1st Class
Joined
Apr 6, 2011
Messages
290
Re: Not sure what to do next - 55HP Johnson problems

Given the age and the lazy idle
I think I would give it a
Soak with engine tuner
 

tdrummond

Cadet
Joined
Aug 2, 2011
Messages
15
Re: Not sure what to do next - 55HP Johnson problems

think the timeing on these motors should be around 19deg top dead center i
 

tdrummond

Cadet
Joined
Aug 2, 2011
Messages
15
Re: Not sure what to do next - 55HP Johnson problems

i have a full workshop manual if you want a copy a big file but full off great stuff on trubbel shooting will need your email address to send file to let me know if you want it or can it be sent throught here 334mb so big
 
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