1957 Goodyear 12 hp, starting point for carb adjustments

[lmuss53]

I have this late 50's vintage Goodyear that looks a lot like an Evinrude 18 my brother owns so if need be maybe this can be moved to the OMC section. I looked it up and ordered a rebuild kit for the carb on ebay and when it came it was an OMC kit that fit, so more that makes me think it is an OMC product.

It is back together and will start and idle pretty well, but I am sure the mix screws are out of whack since the guy who owns it told me he ran them in and out trying to get it to run.

My question is can anyone give me a starting point for the mix screws so I can work on getting it running.

 

[F_R]

Yes, it is an OMC motor. If you are able to start it, the needles are somewhere close. What you need to do now is get it on a boat, on the lake and make the final adjustments. Run it at full throttle and turn the high speed needle (the lower one) to the right till it starts to lose power. Then back it off to the left till it regains power. Do the same with the slow speed needle, but at slow idle speed. When it is too far to the right (lean) it usually will cough or sneeze, maybe even stall. Turn it back to the left till it stops sneezing. Then forget they are there except for a minor tweak if necessary.

 

[lmuss53]

Thank you, I have the idle close, the problem is I won't be able to go along when the motor gets put on a boat again. I was looking for some close numbers to have a starting point on the lake test, especially for the high speed knob.

I have it in a barrel now and it's hard to get much of a high speed test there.

 

[F_R]

Exactly. That's why I said the next step is to get it on the lake. If you are looking for the "official" numbers they are 3/4 turn open on the H/S and 1-1/2 turns on the slow speed. But that's just close enough to get it running. You got it running, so it must be somewhere in the ball park.

 

[lmuss53]

OK and thanks again, we'll get it on the water and see what happens.

 

[lmuss53]

Well no joy, it still falls apart on the high side. It wanted the high speed screw about 1/2 turn from all the way in to even try at all.

Basics are good hot spark on both cylinders, 90 psi on each cylinder, fuel pump gives a teaspoon sized spurt on each pulse. It starts and idles, but stumbles around when you try to give it the gas. Timer base is turning and that all appears to be working normally.

It has a set of pretty vintage Champion 5847 plugs in it, gapped at .030, is this the right plug? If not what is a good replacement?

Any other advice is also deeply appreciated.

 

[F_R]

I have no clue what a 5847 plug is. Maybe it is the Goodyear number (original plugs?). Correct Champion # is J6J (now J6C). When you turn the HS knob towards lean, does it reach a point that it speeds up and wants to quit? Ideal setting is just before that happens. I'm thinking perhaps you still aren't lean enough.

 

[lmuss53]

I'll get a set of J6C plugs and have another go at it, thanks for the reply. The 5847 looks like a weedeater plug, and is still available.

Forgive my ignorance, turning the screw out (counter clockwise) will allow more air in and make it more lean, correct?

 

[F_R]

The screw/needle controls gas, not air. Think of it as a faucet (because actually that is what it is). Opening the faucet (counter-clockwise) lets more gas flow (richer). Closing the faucet (clockwise) restricts gas flow (leaner). Too rich will make it blubber along roughly because of too much fuel. Too lean will make it conk out because of not enough fuel.