1959 Johnson 35hp Super Seahorse carb/fuel problems

[MichaelHorowitz]

I have a 1959 Super Seahorse 35hp with electric start on a 1962 14-foot Mirrocraft runabout. For the last two summers it can start in gear (at high RPM's) but not in neutral with the throttle limit. It needed a lot of gas to run, too much for limit.

I finally realized that I had mistakenly left fuel in the motor over a winter, and went through the carb twice, cleaning out the orifices with air and carb cleaner, removing the jets, cleaning the bowl. While at it, set points and replaced plugs. Put new primer bulb on fuel line. Checked compression - 120 in both cylinders. Adjusted low speed: gently seat, then 1-1/2 turns out. Adjusted high speed: seat, then 1 turn out. Put knobs at 12 o'clock, tightened screws. Re-attached linkage. Put all back together and ran in 55 gallon drum. Ran better than in years. Started in neutral. In neutral, throttle all the way down, still purred at idle. Throttled down has always killed my motor. Ran 5 minutes. Tried in gear. All worked. Brought to lake for camping trip on island 2 miles off shore. Figured I would set high speed on lake with friend.

At Dock, boat would not start, again, and had to get family in and start in gear. Ran sluggish at best. Died on the water half way, then after 15 starting attempts, got us to the island. At island checked motor again. Priming causes fuel to exit high speed jet behind butterfly, and the small intake to right of main carb intake. Ball never gets hard. Well, it did once, with fuel not coming out, and it started in gear, but died in a few seconds for what sounded like too rich mix. Then back to fuel pouring out of carb air intake.

I mess with again, prime sends fuel out butterfly again. I remove starter and carb (on water with 1-2 foot waves-never again). Carb looks clean. Float seems to float. Put back together. Stayed at motor while wife on key start. I work throttle from linkage and bypass throttle limit. Starts, run for a few seconds, fuel pouring out of butterfly. Cannot idle. Killed starter battery in frustration. Towed to shore.

1. Should I order rebuild kit? Sounds like it can only be the needle if fuel not stopping. if so, why, beyond murphy's law did it run flawlessly in the drum?

2. How can/should I set or adjust the needle/float assembly? I did remove it to check the needle and clean out its orifice. Cork float seems OK. What should I do to check it better.

Thanks ahead for any advice.

 

[MichaelHorowitz]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

By the way - never removed welch plug in top carb housing. Not that I am having a fuel delivery shortage, thought it probably good to emntion. Just blew air and carb cleaner through orifices to make sure they were clear.

 

[HighTrim]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Replace the needle and seat.

The float should be parallel to the carb body when upside down in your hand, and not cockeyed. I like the unhinged end just slightly higher than the hinged end to ensure the needle seats.

 

[MichaelHorowitz]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Shouldn't I replace the float as well...just to be sure. Maybe my carb cleaning ended up washing some shellac off the float and it is now logged...

If I could get this in order the motor otherwise runs great. Especially for a 53 year old motor. 7 years older than me...

 

[HighTrim]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

You did not remove the float before you soaked it?

The float can either be re coated with airplane dope, or of course simply purchase a new one.

 

[MichaelHorowitz]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

You did not remove the float before you soaked it?

The float can either be re coated with airplane dope, or of course simply purchase a new one.

I didn't soak it. I removed the float and used carb cleaner spray and air to clean the carb. I only removed the float to get to the black goo that was at the bottom of the bowl, then put it back in. The boat did run great after that for the barrel test (low speed idle and high speed in gear), just not on the water a few hours later. In any case, I bought a new one and a rebuild kit. I am pretty confident that after I cleaned the carb there was still some gunk in the hoses or the pump. I had to ream the gasket at the overflow because it was clogged with goo when I cleaned the carb. I am not sure what to soak it in, but pretty sure the next time I clean it I am going to pump the primer to run gas through the hose at the pump, then again through the hose at the carb before I reassemble. Live and learn, I guess.

Ethanol seems to be a nightmare. Is there a step by step to cleaning the carb?

 

[kfa4303]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Hi Mike. Here's a great How-to link for cleaning and rebuilding a carb. It's for a slightly different model than yours, but all of the steps are the same. That's the beauty of these old gems, once you can fis one you can pretty much fix 'em all. Pay special attention the section on removing the welch plug. Oh, and WEAR EYE PROTECTION when using aerosol carb cleaner! That stuff can go in one passage and shoot back pout another in no time. Good luck. Holler if you get stuck.

http://www.outboard-boat-motor-repa...hnson 5.5 HP 1954-1964 Carburetor Tune-UP.htm

 

[HighTrim]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

The carbs that have had fuel left in them forever, and have varnished need to be soaked.

I start by taking the carb right apart, and soaking the parts overnight. Heavily varnished carbs need something aggressive like a carb dip, but for light cleaning Pine Sol will be fine and easier on the body. If they are not heavily varnished you may not need the soak. Then blow out all passages with an aerosol carb cleaner. I myself like to use OMC Engine Tuner. Wash with hot soapy water, then blast dry with compressed air. Ensure all passages are clear and clean. Reassemble.

Always change the fuel lines if they are original when cleaning the carb, the originals were not ethanol resistant.

Ethanol is not really a nightmare. It keeps your system clean. It is only a nightmare on dirty motors, as it breaks up debris and gets it lodged into all kinds of nooks and crannies. Once clean, you should not have a problem.

 

[MichaelHorowitz]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Thanks to High Trim and KFA4303.

I am mechanical, but not a mechanic. I will do my best. Have compressor and tools. Bought rebuild kit with float (Johnson/Evinrude) will rebuild this weekend. Had it open three times, it is not shellac-ed, but did have black goo. I am assuming that removing the welch plug at the low speed jet end will be good. What about replacing all of the fuel lines with ethanol resistant/compatible lines? I will clean carb with spray. I will wash the carb with soap and hot water and dry with air. Going to replace seat, needle, float, packing, block intake paper gasket and carb bowl gasket.

Should I clean out the fuel pump other than replacing the filter bag? I also bought a 3/8 inline fuel filter to place before primer bulb and am committed to buying ethanol free gas, or mixing with treatment if I cannot.

Boat mechanic at local shop told me to use throttle plate foam cleaner for cleaning carb. I am excited to get it running well. low speed 1-1/2 turns out high speed 1 turn out.

 

[kfa4303]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Hello again Mike. Sure, you can use ethanol resistant fuel lines, but if you can't find them that's ok too. Either way, just make sure that the fuel line leading from the tank to the fuel pump is of the thick-walled variety as it is under vacuum/pulse. Black goo is never good in a carb, but you're on the right track. Just remove the welch plugs and any and all packings and gaskets and thoroughly clean the carb body, let dry, then spray all of the passages with aerosol carb cleaner. I just use the auto store brand. Look for generic "Carb + Choke Cleaner". (wear goggles so that stuff won't get in your eyes) Once it's all squeaky clean, reassemble the carb using the link below as a guide. It's for a slightly different model, but all of the steps are virtually identical. It will also tell you where to set the needles, but you'll still need to tweak them again once you're on the water. Cleaning the fuel pump never hurts. Just make sure you don't damage it in any way. However, if it needs to be rebuilt, you can get a kit here at iboats, I believe. I have also installed a small inline fuel filter on my own motor like the one in the pic below. I put it between my fuel pump and the carb just for and extra layer of protection. It also allows me to see that the fuel pump and primer blub are working. If you can find and afford ethanol free (aka "marine gas") go for it, but if you can't you'll be ok. I just use regular old 87 octane in my '66 20 hp and other vintage motors, and so far so good. Btw no need to run high grade gas either. It's actually less than ideal because it delays detonation every so slightly which reduces performance a bit. Besides, 90-something octane didn't even exist in 1959 when the motor was made Just run 24:1 mix, 5.5 fl. oz. of TCW-III marine 2-stoke outboard oil (any brand is fine) to one US gallon of 87 octane while using Champion J6C spark plugs and you'll be good to go. Sounds like you've got a plan. Good luck. Holler if you get stuck.



http://www.outboard-boat-motor-repa...hnson 5.5 HP 1954-1964 Carburetor Tune-UP.htm

 

[MichaelHorowitz]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

KFA4303,

Thanks again. Here's my holler(s).

Local gas station 15 miles away sells non-ethanol gas. If not I use gas enzyme treatment, like Star Tron.

I have had conflicting advice on the mixture. Most tell me to run 50:1 since TCW-III is so much better than SAE 30 was in 1959, and the motor has roller bearings. The airplane mechanic who sold me the motor refurb-ed it and actually wrote 32:1 in yellow paint on the new starter he installed. Then there's those who say to stick with the original 24:1. Even my local boat shop sold me Evinrude TCW-III and told me to mix 50:1. 24:1 is half the oil of 50:1. So what are the benefits of 24:1 if 50:1 works? I hate leaving rainbows on the lake if I can help it.

Also, the last time I had the carb apart, the lower "needle" (high speed) actually has a blunt end where it terminates in the bowl. Isn't it supposed to be tapered to a point (hence the term needle)? Hard to tell in the parts catalog diagram.

Oh and where'd you get that little clear inline fuel filter? Looks like a motorcycle filter.

-M

 

[Willyclay]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

24:1 is half the oil of 50:1.-M

Wrong, you have it backwards!

 

[HighTrim]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Run 24:1

Ask the dealership if they will warranty your powerhead running at 50:1?

I have hundreds of 50s OMCS. A room full of ones with blown powerheads, worn crank journals, etc... from "Joe down the street..." telling the previous owner to run at 50:1

The high speed needle is blunt like you mentioned, it is simply a faucet if you will, to over simplify it.

 

[kfa4303]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

+1!!!! yup 24:1 it is (50:1 has half the amount of oil, which isn't enough. They didn't switch to 50:1 until later models. I run 24:1 in my '66 20 hp with no issues what so ever). That works out to about 5.5 fl. oz. of TCW-III marine outboard 2-stroke motor oil to 1 US gallon of 87 octane gas. I don't use any other additives, except for the occasional Seafoam treatment. I got the little inline fuel filter from auto store for about $2. The lower needle is/should be blunt like you mentioned. Here's a great link to help you with a carb rebuild.

http://www.outboard-boat-motor-repa...hnson 5.5 HP 1954-1964 Carburetor Tune-UP.htm

 

[MichaelHorowitz]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Willclay,

Yes brain backwards on that. Half as much oil at 50:1. I really meant that in my head.

 

[Willyclay]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Most of us have done the same thing or worse. Good luck with that great old motor. I enjoyed mine for ten years.

 

[MichaelHorowitz]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Rebuilding as I type. Low speed needle has threaded ferrule under packing nut that doesn't show in diagrams. I assume that the packing goes between that ferrule and the packing nut.

Also there is cork packing and a nylon washer. I also assume one packing washer, the nylon over then the packing nut?

I think I need to look at the parts catalog for my model, which I assume is RDSL-21 (A or B). My motor ID plat is missing off of transom clamp. Still have S/N on motor, but no model number there.

I have a pink plastic washer in the rebuild kit (for my specific year) that I cannot ID and more packing than I know what to do with. The high speed nozzle tube (cast from top portion of carb) is chewed a bit on one side where the boss gasket should seat. It looks like it will seal, but unsure until I try it. I have included pictures of my upper carb section with the high speed nozzle tube chewed up, etc. Everyone always says post pics, so I am..



My package with the extra packing and washer...View attachment 159503

My old float, which looks fine.

By the way, I really reamed my old float needle seat and got a bunch of crud that was holding the needle from seating 100%...bingo!

 

[kfa4303]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

glad you got it apart and are getting the goo out. This link can help you put it all back together again.

http://www.outboard-boat-motor-repa...hnson 5.5 HP 1954-1964 Carburetor Tune-UP.htm

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/377808/37780800001.htm

 

[HighTrim]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

Glad you got it!

On the low speed, you will have the threaded bushing that the needle threads into, then a washer, the low speed packing, another washer, then the packing nut

On the high speed, simply put 3 of the cork packing washers in, then the packing nut

 

[tx1961whaler]

Re: 1959 Johnson 35hp Super Seahorse carb/fuel problems

The black goo is probably from your fuel lines coming apart from the inside. They need to be replaced asap. The little in-line filter will help also.