1961 Johnson Sea Horse 75hp

[Clippership821]

I've got spark but won't start now. It took me a good 15 minutes to get it running the other day. I kept on the trailer and just backed into the water. Because I'm tired getting it in the water and the having to put it back on the trailer when it doesn't start. It started finally. After I gave it as much gas as possible in neutral. will not idle easily and then dies. Now can't get it to start. Also, bulb on fuel line doesn't stay hard when I pump it up. any ideas? Thanks

 

[Chris1956]

Re: 1961 Johnson Sea Horse 75hp

Clipper, Normally those motors start easily. It is new to you, or have you done something to it? Motors need three things to start. Air, fuel and spark. You should see a sheen of fuel in the water when it cranks. If no fuel spill, you have carb/fuel pump issues. If you see the fuel, is the spark timing correct? Points should open just as timing marks on dissy pully align with dissy pulley base, and also 90 degrees later when second set of points open. When you spin the dissy pully, by hand, spark should snap with a blue color. If not, coil, points or condenser is defective. Check the coil for cracks, and clean the points and file them a bit, and regap. Replace the condenser if necessary.

 

[Clippership821]

Re: 1961 Johnson Sea Horse 75hp

I got the motor last year and it had a few problems. It was only running on two cylinders so I got the points kit and replaced everything down to the rotor. fixed that. It also had overheating problems because of the water pump. Replaced that ...all good. It started and ran fine. Put her to bed for the winter. Started right up this spring and ran good once. It died coming into the the dock and I couldn't get it to start. I put new gas in. 1:25 mixture and it's only start once since and ran horribly and will not idle. That's it. I'm at a loss. I'm almost sure the fuel pump or the carb has never been rebuilt. Thnks for the fast response. BTW it's got really good spark. I checked that out before posting.

 

[Evinrude Boater]

Re: 1961 Johnson Sea Horse 75hp

Sounds like the main jet is stuck open and fuel is just running through. There might be a small obstruction in the jet. The carburetors likely need to be cleaned thoroughly and have the orifices blown out with compressed air. That worked wonders for mine.

 

[Clippership821]

Re: 1961 Johnson Sea Horse 75hp

Thanks Evinruder....Is that a matter of complete dissy and what kit do I need to rebuild carb?

 

[Evinrude Boater]

Re: 1961 Johnson Sea Horse 75hp

Carb kits contain gaskets, jets and usually a float. I only cleaned my carb, didn't replace anything, not even the gaskets and it works fine. I guess it depends on what condition yours is in. If the cork float has soaked up gas then it's not going to float in the bowl and turn off the flow of gas when you pump up the bulb. If there's so much as a grain of sand in the main jet, the needle won't close and gas will continue to flow flooding your engine. Take it apart as much as you can and clean everything with carburetor cleaner and blow it dry with compressed air.

 

[tashasdaddy]

Re: 1961 Johnson Sea Horse 75hp

laings has the kit for each carb and float. i would get both.
http://www.laingsoutboards.com/newp...ncludes Gale, Sea King up to 1963, and others

 

[Clippership821]

Re: 1961 Johnson Sea Horse 75hp Idles Rough

Re: 1961 Johnson Sea Horse 75hp Idles Rough

Got the carb kit in with a new float. Re-synced the engine. Very hard to start and would not hardly idle. Idles very roughly when did start. Checked the plugs after ..very black and sooty. I'm starting to suspect the gas mix. I used 2 stroke chain saw oil last batch mixed 25:1 Gonna put in a fresh batch mixed 50:1 with proper marine engine oil. Any ideas? Thanks.

 

[Chris1956]

Re: 1961 Johnson Sea Horse 75hp

That motor should run just fine on a 24::1 mix. I believe you may run that motor on a 50::1 mix, but you should check with Joe Reeves to be positive.

If it is running poorly on a 24::1 mix, the mix is not the problem, even if it is chainsaw oil.

Do you have adjustable idle mixture screws? If so, have you adjusted them to spec? How about high speed mixture adjustments? Are you sure the float is set properly and the inlet needle sealing well?

 

[Clippership821]

Re: 1961 Johnson Sea Horse 75hp

yes adjustable low speed idle. Fixed orifices on the high thanks

 

[R.Johnson]

Re: 1961 Johnson Sea Horse 75hp

1961 75 without a compression check, won't respond throwing part's at it. Let's go back to basic's here.

 

[Evinrude Boater]

Re: 1961 Johnson Sea Horse 75hp

Where did you set the low speed screws? Should start at 1.5 turns from lightly seated.
Does the fuel line bulb stay hard now?
Mine starts immediately by squirting some fuel in the carbs and choking it. Otherwise it takes a lot of cranking.
When you try again with fresh fuel see if you can run it wide open under load for a few minutes to clean it out. At an idle, especially a poor idle, it's going to load up.

 

[Clippership821]

Re: 1961 Johnson Sea Horse 75hp

Thanks Evinruder...Got em set out 1.5 turns like the manual suggests. The bulb is staying pumped up now. Did a pump up pressure test on the fuel pump and it passed. No leakage in the diaphragm....however the only thing the carb kit did not come with was the packing for the low speed needles. Would that be a factor? I'm gonna check the points to see if they've shifted as well. The only other thing I can think of is # 3 plug is in there by the last threads. In fact, I can't get a new plug in because of the washer. It almost needs a helicoil. I probably should do a compression check on that cylinder at least. I got the plug insert ready to go. I just didn't want to do it if I didn't have to.

 

[Chris1956]

Re: 1961 Johnson Sea Horse 75hp

Clipper, My '59 Johnny V4 had orings on the idle needles. Are you missing these?

 

[Clippership821]

Re: 1961 Johnson Sea Horse 75hp

Clipper, My '59 Johnny V4 had orings on the idle needles. Are you missing these?

No..Mine has packing and washers.

 

[Joe Reeves]

Re: 1961 Johnson Sea Horse 75hp

Chris..... No offense intended here. On the 1958/59 V4 50hp model, the high speed adjustable needle valves incorporated "O" Rings, but the slow speed adjustable valves had packing washers and threaded jam nuts.