1960 Evinrude 10 hp only runs when choke is pulled

This topic has 8 replies, 6 voices, and was last updated 3 years, 6 months ago by fleetwin.

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September 17, 2020 at 3:10 pm #216677
MARC BOUCHER
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Any advice for what might be wrong with my 1960 10 hp Evinrude? It only runs when the choke it pulled out. I’m thinking it is probably something obvious, but I can’t figure it out.

Just a funny story that goes along with this motor from last week… I was running it without the starter recoil connected and was just using a 1/2″ socket on a cordless drill to start it (as I get older my arm doesn’t appreciate all the pulls I do) and I dropped the whole shebang into the Lake Superior. I’ve always known that was going to happen one day, and last week is when it happened! Time to put the recoil back on!

Thanks in advance for any help!
Marc

Boats: '47 Dunphy, '64 Starcraft
Motors:
'53 Evinrude 25; '54 Evinrude 7.5; '55 Evinrude 7.5; '56 Evinrude 30 Lark; '56 Evinrude 16; '58 Johnson 18; '60 Evinrude 10; '64 Evinrude 40
September 17, 2020 at 5:05 pm #216686
fleetwin
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US Member - 2 Years
Mark
Did you try richening up the needles a bit? Does it run OK at low speeds, and falter at high speeds, or can’t you get it to run at low speeds (start up). If richening up the needles won’t help, you will probably have to pull the carb apart…
Have you confirmed the fuel/oil supply is fresh and free or water? Did you try a different tank/hose? When was the last time the engine ran OK?
Another thought….Is the carb sync OK? Keep in mind that the butterfly is opened slightly when the choke is pulled…The engine won’t run correctly if the linkage is messed up and the butterfly is hanging open when the choke is closed.
- This reply was modified 3 years, 7 months ago by fleetwin.
September 17, 2020 at 6:39 pm #216706
frankr
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What have you done so far? ANY 1960 OMC twin has cracked coils unless they have already been replaced. If they are cracked, you are wasting your time until you do.
September 23, 2020 at 1:17 pm #217169
MARC BOUCHER
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Actually I replaced all the coils about 7 years ago and it was running fine until I tried to fire it up this year. Yes, I tried richening up the needles, but will try it again – I will also take a look at the throttle needles – some of my other motors seem to have benefitted greatly from new ring washers (or whatever they are called). But yes, to answer your question, it doesn’t run either on high or low throttle without the choke being out. It actually runs pretty well with the choke out though! Once I push it back in, the motor just dies. Ah – the linkage – I should check that. So you are saying that when the choke is closed, there needs to still be air coming through the carb – that is a great point, maybe that is my problem. That would explain it at least!

Just a follow up on the comment about the cracked coils – if they indeed were cracked, the motor wouldn’t run at all, right?

Boats: '47 Dunphy, '64 Starcraft
Motors:
'53 Evinrude 25; '54 Evinrude 7.5; '55 Evinrude 7.5; '56 Evinrude 30 Lark; '56 Evinrude 16; '58 Johnson 18; '60 Evinrude 10; '64 Evinrude 40
September 23, 2020 at 2:10 pm #217171
outbdnut2
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I’m thinkin’ you probably have some dirt in the carb blocking the gas path – it may be caught in the needles as others mentioned – You may be able to fix without taking the carb apart by unscrewing the adjustment needles all the way out and spraying carb cleaner in the holes you took them out of. Use a can of carb cleaner with the long tube to get it way it the hole with some pressure. It may just move the dirt and it could run awhile and block again, or if you are lucky, it may blast it right on through.
Dave
September 23, 2020 at 2:46 pm #217174
dave-bernard
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Or the gasket is swollen at the idle passage.
September 23, 2020 at 3:33 pm #217176
cajuncook1
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Marc, do yourself a favor and start with the basics.

Check for spark. Even though you changed the coils 7 years ago doesn’t mean the points can’t get dirty or the condensers go bad. Get an open gap spark checker and check top and bottom cylinder. Should get a good consistent sharp blue spark that jumps 1/4 inch gap. Once you rule out ignition, then move on to fuel delivery.

Fuel delivery:

Do you have a pressure tank fuel delivery system or a fuel pump?

fuel pump
– usually a fuel pump does not go bad in few years. If it is an aftermarket fuel pump then reliability maybe questionable.
– check the fuel pump for cracks in the cover that sits over the screen. It could allow air to be pulled in and affect delivery.
– make sure the fuel tank vent is open or the valve is patent. A closed fuel tank system that does not allow air to enter the tank will create negative pressure in the tank and prevent the fuel pump from pulling enough fuel from the tank to push to the carburetor. Thus requiring the choke to be maintained for fuel delivery.
– check your fuel line and connections to the motor and tank, the whole length.
– make sure the fuel hose is oriented in the right direction. I think the bulb has anti-reflux valve.
– fuel tank’s pick up line screen is partially clogged with trash/clumped oil.
– water accumulation in your fuel.

Pressure Tank:

– Your tank’s pressure maybe be leaking due to a leak in the tanks gasket.
– Poor o-ring sealing
– Tank’s pressure relief valve is faulty or dirty.
– Check your dual line fuel hose to see if the there is cracks or damage on the air side from the exhaust manifold nipple.
– fuel tank’s pick up line screen is partially clogged with trash/clumped oil.
– water accumulation in your fuel.

OR
I know a lot of people spray carburetor cleaner in all holes the carburetor while it is attached to power head, but carburetor cleaner can damage gaskets and plastic. Turns them soft. So, it is better to take the carburetor off and disassemble it and clean it with carburetor cleaner when all the gaskets, packing and high boss gasket are off of it.

These are just a few thoughts, that may help you out.

Cheers, I hope you get it resolved soon and back on the water.

Cajuncook1
- This reply was modified 3 years, 6 months ago by cajuncook1.
- This reply was modified 3 years, 6 months ago by cajuncook1.
September 23, 2020 at 3:40 pm #217178
cajuncook1
Participant
Oh, disregard the pressure tank suggestions. I was getting your other post of the 1952 7.5hp motor mixed in with my thoughs. The 1960 Johnson/Evinrude 10hp motors had fuel pumps.

Cheers,

Cajun
September 23, 2020 at 7:59 pm #217198
fleetwin
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US Member - 2 Years
Like Cajun says, stick with the basics… When we skip over basics, we make false assumptions and often times create problems that weren’t there to begin with…
I think what I hear you saying is that the engine ran fine last year, but wouldn’t work without the choke when you first tried it this season, do I have it right?
That engine has a separate filter, did you check/clean it? Any signs of water in the filter bowl. Will the engine run without the choke if an assistant pumps the fuel primer bulb constantly?
Is your fuel/oil supply fresh and free of water? Did you try a different tank and hose?
The engine won’t run at low or high speeds without the choke, correct? If so, you can forget about my comments about throttle linkage, unless the butterfly is jammed or something obvious like that… Just a guess, and forgive me for not reviewing this post, but it sounds like your carb got gummed up over the winter….
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