1956 5.5hp Fisherman won't idle

jasoneon

Cadet
Joined
Jun 27, 2011
Messages
6
A little history:

Motor had been sitting for 3-5 years when I got it. I cleaned out the carb, threw in new spark plugs and it would hit and run but only for a couple of seconds at a time. So I figured it needed the points checked and maybe new coils or wires. Well I completely disassembled the engine (even the rings off the pistons to clean the carbon off). I replaced every gasket, the points, the coils, the wires, the water impeller and every seal in the lower unit. I also replaced all the fuel lines, the o-rings in the fuel connector and the diaphram and gaskets in the fuel tank.

I mixed up 2 gallons of gas with 1/2 quart of 2 cycle marine oil and even cleaned the carb again. It ran like crap and so I drained the gas and mixed up 2 gallons of gas with 1/2 quart of straight 30w non detergent oil and put in another set of fresh plugs (they were covered in oil). It runs much much better and will rev up quick and has a lot of rpm. However, it will not idle down very low at all. If I turn the handle to the start position it will idle for a couple of seconds then stumble and die. If I turn it back to the shift or slow position it dies immediately. I'm wondering if it has something to do with the timing plate. It seems to me it has some slop in it. Here's a link to video showing what I'm talking about it.

http://www.youtube.com/watch?v=ylZ41EeQqrQ

Forgot to mention originally that the engine has 75ish psi compression in both cylinders.
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 1956 5.5hp Fisherman won't idle

Where have you got the low speed needle set, 1 1/4 turn out from lightly seated?
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1956 5.5hp Fisherman won't idle

this wont help with your idle problem, but it appears as tho you are missing a small piece of rubber "tubing" on the throttle linkage. both my dead 56 johnson 5.5 and my nice working 57 johnson 5.5 have that on the linkage. both motors....in the start position......, (not sure what the part is called), but i will call it the arced peice that pushes the throttle open, is about 1/3 of the way to wot,and just begins to touch the trottle in the shift position. i can post pics of the rubber piece on the throttle arm and the position of those parts at different throttle settings if it would help.
 

jasoneon

Cadet
Joined
Jun 27, 2011
Messages
6
Re: 1956 5.5hp Fisherman won't idle

The low speed is actually more like 3/4 turn from seated and the high speed is a little less than 1/2. It runs best at these settings even though they're nowhere near what is recommended in the manual. If richen the low end it runs very rough and revs up very slow. Both needles have a fine tip on them and don't show any signs of wear.


I understand what you're talking about nwcove. My next move was to actually put a metal sleeve on the throttle arm so the butterfly wouldn't close as much in the start position. I still wouldn't mind some pictures if you get a chance though. Maybe there's something else I'm missing that I just don't know about. My e-mail is black98rt@suddenlink.net if it's easier for you to e-mail me the pictures. I appreciate the responses guys.
 

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: 1956 5.5hp Fisherman won't idle

Did you install a new carb kit? Did you remove the welch plug and clean the little holes under there? That is the idle circuit.
 

jasoneon

Cadet
Joined
Jun 27, 2011
Messages
6
Re: 1956 5.5hp Fisherman won't idle

Did you install a new carb kit? Did you remove the welch plug and clean the little holes under there? That is the idle circuit.

The first time I skipped it, but the second time I removed the plug and installed a new one. I ran welding tip cleaners through all the holes and and blew air through them. I bought another carb I might try out but I'm just not thinking it's a fuel issue.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 1956 5.5hp Fisherman won't idle

I think part of your issue is your link & synch is off. The mag cam should engage the follower arm on the carb at that line on the cam. It looks like it is hitting yours early. The bolt holes in that cam are elongated to allow adjustment.

How much slop is there in the ball gears at the joint of the tiller base to the tiller arm? It does look like something is loose somewhere in that series of linkages...

Your motor never had a roller on the cam follower - it is correct as it is...
 
Last edited:

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: 1956 5.5hp Fisherman won't idle

Could be a small (visually undeterctable) crack somewhere in the carb - I've had that happen - same symptoms as yours. Replaced the carb and the motor ran fine.
 

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: 1956 5.5hp Fisherman won't idle

I don't think your motor ever had a roller on the cam follower...

The 5.5hp models I've worked on haven't had rollers - just the metal shaft riding on the cam. I've seen some pretty good grooves in the shafts from years of riding on that cam.
 

jasoneon

Cadet
Joined
Jun 27, 2011
Messages
6
Re: 1956 5.5hp Fisherman won't idle

I think part of your issue is your link & synch is off. The mag cam should engage the follower arm on the carb at that line on the cam. It looks like it is hitting yours early. The bolt holes in that cam are elongated to allow adjustment.

How much slop is there in the ball gears at the joint of the tiller base to the tiller arm? It does look like something is loose somewhere in that series of linkages...

Your motor never had a roller on the cam follower - it is correct as it is...

As of now the mag cam is pulled out as close to the carb as possible. The linkage seems fairly tight it's just that the whole armature plate can be moved back and forth quite a bit when the handle is in the start position. When the handle is in the fast position or stop position you cannot move the armature plate by hand at all.
 

jasoneon

Cadet
Joined
Jun 27, 2011
Messages
6
Re: 1956 5.5hp Fisherman won't idle

Could be a small (visually undeterctable) crack somewhere in the carb - I've had that happen - same symptoms as yours. Replaced the carb and the motor ran fine.

I'm going to try putting some sealant on top of the welch plug to make sure it's not sucking air there. If that doesn't change things then I guess I'll rebuild the other carb I bought and see what happens with it.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 1956 5.5hp Fisherman won't idle

As of now the mag cam is pulled out as close to the carb as possible. The linkage seems fairly tight it's just that the whole armature plate can be moved back and forth quite a bit when the handle is in the start position. When the handle is in the fast position or stop position you cannot move the armature plate by hand at all.

Actually, the cam needs to be moved AWAY from the carb a bit so that it doesn't contact the follower arm quite so soon... You want it to make first contact right at that mark on the cam...
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1956 5.5hp Fisherman won't idle

from watching your video numerous times, it appears (if its possible) that you problem could be in your tiller handle gears being a couple of cogs off. i will email you pics of the position of mine at various settings.
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1956 5.5hp Fisherman won't idle

wot.jpgslow.jpgstart.jpgstop position.jpg

this looks like different positions as compared to the utube video.
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1956 5.5hp Fisherman won't idle

wot1.jpgslow1.jpgshift1.jpgstop.jpg

this looks quite a bit different than the positions shown in the utube video.
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1956 5.5hp Fisherman won't idle

did you get things worked out?
 

jasoneon

Cadet
Joined
Jun 27, 2011
Messages
6
Re: 1956 5.5hp Fisherman won't idle

Hey sorry I haven't posted anything or thanked you for the pictures (which I really do appreciate). I haven't had a chance to really mess with it over the past week but this weekend I'm going to tinker with it a bit more. I'll post back up saturday with either good news or pictures of boat engine vs sledge hammer.
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1956 5.5hp Fisherman won't idle

lol......dont kill it! it is a keeper!
 

oggiepirate

Recruit
Joined
Aug 16, 2011
Messages
1
Re: 1956 5.5hp Fisherman won't idle

Hi did you ever manage to get to find an answer to the problem... I've got a similar issue with the one Ive got....
 
Top