1976 Johnson Seahorse 6HP Problems

Sarentack

Seaman
Joined
Jun 29, 2012
Messages
60
Well where do I begin?

Got this motor about month and a half ago, it had problems starting up, guy I got it from had it running but indicated it might have a weak fuel pump on it. The Carb float was tar looking, few burns, bridle, I replaced it, but ill get into that in a minute.

From the get go the motor would start with the choke out but could never keep it running. Eventually adjusting the fuel mixture on it it was able to stay running. However in order to start it, I had to put a drill to the fly wheel and run the drill for about 10-15 seconds before it would even crank (I am operating starting it the hard way by using a rope on the fly wheel because the intake manifold in which the pull rope assemble attaches to had a screw hole break)

After that, it would stay running, and then you could use the rope and it start right up. We did that one night all night with an idea to go out in the water in the morning with it since we could start it up so easily even after it sat for 15-20 mins.

Well we get to the Boat ramp, the motor was dead. We couldnt crank it, it wasnt even beginning to show signs of starting and we pulled that rope until we were blue in the face. The boat ramp is only about 1/10th a mile if that away from the house, but the motor was tilted up some on transfer and may of caused it.

So we get it back to the house, couldnt start that thing up for nothing, we were only using a rope because the drill burnt out (Walmart special I took back) So we just say......................

Low and behold about 3-4 days later we got out there to try and get it started just by the pull rope, it cranked up on 2 tries just like that. Apparently this motor if it sets up for half an hour or so after running, its hard to start it up unless it sets for a day or so...I dont know what it is.

Recently I replaced the fuel pump, ($110 new part I may add) and got a carb kit in which I replaced the gasket, float, and all of that.

Well............still nothing, it wont crank off the rope for whatever reason, basically we could use a drill but shouldnt have to.

I cannot figure out what the problem is. I tried starting fluid, that didnt work either. It seems the plugs are getting spark though, I regapped them to .030-.035 twice to make sure they were gapped right. Still nothing.

I am stumped.
 

SeaKaye12

Lieutenant Junior Grade
Joined
Jul 3, 2005
Messages
1,107
Re: 1976 Johnson Seahorse 6HP Problems

Welcome to iboats!

Well; you might as well start from the beginning and work your way through the basic tests:

(1) Check compression. Should be within 10% of each other; 70 lbs or higher is good.

(2) Check Spark; with a spark tester; at least 1/4" gap. Not enough to just see spark on the plug electrodes.

(3) You probably still need more aggressive carb-cleaning in the main jet and main nozzle area...and also under the welch plug on top; that's the idle circuit.

Don't use non-lubricative starting fluid; squirt some gas/oil mix in there instead.

Good luck....
 

Sarentack

Seaman
Joined
Jun 29, 2012
Messages
60
Re: 1976 Johnson Seahorse 6HP Problems

Welcome to iboats!

Well; you might as well start from the beginning and work your way through the basic tests:

(1) Check compression. Should be within 10% of each other; 70 lbs or higher is good.

(2) Check Spark; with a spark tester; at least 1/4" gap. Not enough to just see spark on the plug electrodes.

(3) You probably still need more aggressive carb-cleaning in the main jet and main nozzle area...and also under the welch plug on top; that's the idle circuit.

Don't use non-lubricative starting fluid; squirt some gas/oil mix in there instead.

Good luck....

I am not too savy in motors, it was enough to just get this done, should I be squirtting some gas into the carb?
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1976 Johnson Seahorse 6HP Problems

yep, try squirting some fuel/oil mix into the carb, see if it helps the starting issue.
 

Sarentack

Seaman
Joined
Jun 29, 2012
Messages
60
Re: 1976 Johnson Seahorse 6HP Problems

yep, try squirting some fuel/oil mix into the carb, see if it helps the starting issue.

Well I tried doing that, and it tried to start, it would for about a sec and stutter and then shut off.

So I started looking at the fuel lines to see if they were getting gas, they are from the gas line to the fuel pump, from the fuel pump into the carb, made the sure the place where the hose was attached to was clear so the carb could get fuel, I just dont know.

It did certainly do more by squirting gas into it than it was doing though.
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1976 Johnson Seahorse 6HP Problems

jmo, but you need to do a good carb cleaning, remove the welch plug on top of the carb and soak it, blow it out, run a strand of small copper wire through every orifice and make sure its all clean. ( still see no mention of compresion test? dont spend time and money until you can verify good compression)
 

scipper77

Commander
Joined
Sep 30, 2008
Messages
2,106
Re: 1976 Johnson Seahorse 6HP Problems

keep at it, good advice here. Definitely worth your while to check compression. Hard to start is a definite symptom of low compression.

How is the gas you are using? Are the fuel lines upgraded to ethanol resistant lines. I don't have personal experience with this but I have heard that cleaning a carb fouled by deteriorated rubber can be difficult. The stuff just sticks.
 

Sarentack

Seaman
Joined
Jun 29, 2012
Messages
60
Re: 1976 Johnson Seahorse 6HP Problems

keep at it, good advice here. Definitely worth your while to check compression. Hard to start is a definite symptom of low compression.

How is the gas you are using? Are the fuel lines upgraded to ethanol resistant lines. I don't have personal experience with this but I have heard that cleaning a carb fouled by deteriorated rubber can be difficult. The stuff just sticks.

Not sure how I would do a compression test, I dont have much for tools as I never really work on motors.

I hate to put anymore money into it.

But as for the carb, I put in a kit and it didnt look like much to the carb honestly. It wasnt full of carbon anyway.
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 1976 Johnson Seahorse 6HP Problems

just adding the gaskets/float needle and seat to the carb is just a waste of time and money ( jmo). there are some tiny passages/orifices in the carb that need to be clean. you would be amazed at the difference a carb cleaning will do for a motor that has no other issues.( not sue what you mean by "carbon"?)
 

Sarentack

Seaman
Joined
Jun 29, 2012
Messages
60
Re: 1976 Johnson Seahorse 6HP Problems

just adding the gaskets/float needle and seat to the carb is just a waste of time and money ( jmo). there are some tiny passages/orifices in the carb that need to be clean. you would be amazed at the difference a carb cleaning will do for a motor that has no other issues.( not sue what you mean by "carbon"?)

Well I got it running, yeah it probably was the Carb, I took it off a few times to clean it real good, the issue seemed to be that the needle was sticking, never could figure out the wire on it which was supposed to dangle down from the float, that never worked, it never stayed running until I took the wire off and just stuck the needle into the hole, its not going anywhere anyway because the float has it in there.

However the only way to start it is by squirting a little gas into the intake.

I would take a wild guess that this is a problem in itself since I shouldnt have to do that am I right?

but when I do squirt a little gas into the carb, it cranks right up on the first try usually.
 
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