Johnson Sea Horse 6hp, 1979 model

[vinmega]

Hi everyone. This is my first post on the fourm, and my first foray into being a boat owner! I am very excited.
I live in NJ, my bro in law are putting together a 'duck boat' for hunting and general use for tooling around the rivers and lakes here.
My question is regarding a Johnson 6hp Sea Horse 2 stroke I recieved from a friend. We are both mechanicly inclined, so we decided to get this motor going.
The motor was used in Florida in fresh water. The thing is super clean.
We cant get the the flywheel to move.
We removed the spark plugs, they were pretty fouled, and sprayed PB into the holes.
Can anyone point me in a starting direction to diagnose?
Thanks!

 

[nwcove]

Re: Johnson Sea Horse 6hp, 1979 model

a head gasket is only a few bucks, pull the head and have a look, pics also help, as theres enough knowledge and experience here to diagnose every possibly issue.

welcome to iboats!!!

 

[the machinist]

Re: Johnson Sea Horse 6hp, 1979 model

Can't get the the flywheel to move. Does that mean it will not rotate or that you can not remove it?

Two totally different things, if it won't rotate, then the motor is siezed up either the pistons OR the lower unit. If you are referring to removing the flywheel, then that is a totally different story & probably needs a puller.

 

[vinmega]

Re: Johnson Sea Horse 6hp, 1979 model

First off, thank you all for the welcome to the forums. I appreciate the help.
Can't get the the flywheel to move. Does that mean it will not rotate or that you can not remove it?
I cannot rotate it. The puller cord is all connected, and the little plastic 'gear' rises up to engage flywheel, but flywheel is not rotating.
We took the plugs out and sprayed some PB in the spark plug holes yesterday.
I did not try to take the flywheel off buy the bolt on top yet.
What should I do next?

 

[nwcove]

Re: Johnson Sea Horse 6hp, 1979 model

as i mentioned before, id remove the cylinder head and have a look in there, a head gasket is cheap. and if there is any serious corrosion issues, you might save yourself some money and grief.

 

[vinmega]

Re: Johnson Sea Horse 6hp, 1979 model

UPDATE:
After blasting it with PB and WD40 in the spark plug holes, we got the flywheel to turn. The pull cord worked, we heard a 'put put' noise like it was pumping, so I imagine that this means compression is OK. Next, I am going to get a gas can and power it up in a barrel.
I will report back after getting the motor going.

 

[vinmega]

Re: Johnson Sea Horse 6hp, 1979 model

OK, so here is an update on this old boy. We got new plugs for it, and apparently they recommend a new type of plug for this motor.
We tested it out and have spark.
We changed out the gear case oil, and mixed some fuel. Opened the choke, and after about 5 pulls it putted for about 1 second and shut down.
So we have spark and compression.
My next move it to take the carb apart and clean it with some gun scrubber and get the gunk out...
I also noticed that we had some gas on the outside of the fuel dist, and by the carb. We may have flooded the motor...
Any thoughts?

 

[nwcove]

Re: Johnson Sea Horse 6hp, 1979 model

you really should check the compression, but a carb kit is the next step.

fuel on the outside of the "fuel dist"?......need more info.

 

[vinmega]

Re: Johnson Sea Horse 6hp, 1979 model

OK, so we replaced the fuel filter, and carb. A couple of things. It initially started right up and ran like a champ. The little 'lip' under the flywheel that touches the roller for the carb (cam roller?)kept moving. For example, when I put the throttle knob to the start position, the 'lip' was not lined up the the cam roller. There are 2 lines on the 'lip' that should supposedly line up with start. The 2 marks on the lip when lined up with start was more of a slow speed.
Second thing, the motor ran erratic, I kept choke/un choke/choke/unchoke to keep it alive after a while. If I pushed the choke in it would die, so I kept open/close/open/close to keep it alive. When I went to hard on the throttle, it died.
Third thing, the rich/lean needle. How tight to I make this? I used channel locks and tightened it all the way in and you cant hand turn it as its all the way in and tight. It seemed that as I backed it out from the fully tight position the motor ran really rough. It was also smoky as hell.
So not sure what I did here, but any advice on how tight this should be is helpful.
Also noticed at the exhaust port there was black oil, and the tank we were running it in had black oil blobs in it.
Any advice? I really dont want to take this into the mechanic as I think we are close.
Oh, and compression was within 5 of each other and about 120 per cyl.

 

[vinmega]

Re: Johnson Sea Horse 6hp, 1979 model

The 'lip' I refer to is mounted to a 'plate' below the flywheel.

 

[kfa4303]

Re: Johnson Sea Horse 6hp, 1979 model

Hi vinmeaga. Don't worry about the oil in the test tank, that's normal on these old 2-stoke motors, and shouldn't be an issue on the open water. These old OMC motors were designed to run ion Champion spark plugs, so that's what most of us use. I believe you'll want Champion J4C plugs. I believe the "lip" you're referring to is the roller cam. There should be two little screws on it's underside that can be tightened to keep it in the desired position. They can be a pain to get at on some models, but be patient and you'll get 'em. Do a search here in the forums under link-n-sync and you'll see how to adjust it properly. Here's a link that can walk you through the proper way to adjust your carb too. You're almost there. Keep us posted. Holler if you get stuck.


http://forums.iboats.com/showthread.php?t=167352

 

[AlTn]

Re: Johnson Sea Horse 6hp, 1979 model

if you'll google..Leeroy's Ramblings...he's written a section on the 6 hp. maintenance...for future reference..that low speed idle mixture needle shouldn't ever require pliers to seat or adjust...loosen the nut on the outside of the carb where the needle goes in and you should be able to turn it with your fingers, if not, unscrew the needle completely and remove some of the packing and try reseating it again with your fingers..it'll seat lightly and won't require a lot of pressure..back it out 1 1/2 turns or so and then tighen the nut enough so that you can turn the needle with the knob..set the knob at the mid point so that you're allowed to turn it 1/2 turn in either direction...ccw richens the mixture..cw leans it...it's important that the needle has an even taper with no "bands" or flat spots near its point

 

[vinmega]

Re: Johnson Sea Horse 6hp, 1979 model

Thanks guys, I am going to have some more time tomorrow. So I will report back as I make progress. To get to the plate that the cam roller rests on, do I need to take the flywheel off, or is there a way to tighten that plate without removing flywheel?
I am also going to back out the low speed needle to where it is seated and try from there as well. I am going to have to cut some new threads as we striped the knob end.
thanks