Help with a 67 johnson 20 horse.

I got this with my boat and we got it started (after my dad informed me I had the fuel line backwards), but he had to use ether to get it to start. Once it started it would run. There is a knob between the choke and stop button that we don't know what it is for. It is connected to something in the carb through a linkage type thing. Would this be a fuel adjustment?

Also, there is oil leaking out of a hole in the lower part, but it is not nearly as thick as the lube you would use in the lower unit. Does anyone know what this could be?

The streak is the oil, it is coming out of the hole that is pictured.

Thanks

Another question I have is what ratio for the fuel does this motor use?

The knob is a idle speed, or lean rich adjustment. It is connected to the needle valve in the carb, and adjusts the amount of air that mixes with the fuel in the combustion chamber. You need to idle the motor, then when warm, mess with this knob till the motor sounds like it is running the smoothest. May need to pull the linkage from the knob, and manually move the needle valve by hand, as it will go farther than the knob will. General rule of thumb is to start by turning it all the way in, then backing it out 1.5 turns. Then, hook up the linkage, and fine tune it from there.

I can't see real well where the lube is coming from. Could you take it to MS paint or something and highlight the oil line with a brighter color?

Here is a labeled picture. I tried brightening it a bit in Photoshop. Mac's don't have MS paint

Like I said, this oil is no where near as thick as what you lube the lower unit with.

What fuel/oil ratio should I be putting through this?

Thanks for the help.

Alright, much better with color. I am led to believe that is lower unit lube, solely by the fact that I don't believe there is any other passage down there. Exhaust is let out a bit higher than that, so it wouldn't be carbon and unburned oil, unless the passage was different in '67 than it was in both earlier and later years. Does the hole look factory, or "aftermarket" (okay, lets say accidental :lol: )? Also, have you run the motor in water yet? If so, I would drain the lower unit lube, and look for water, or milky colored lube coming out. If you haven't run it, and the lube had been changed after the last time it was ran, it would be kinda pointless to check for water.

That motor should be alright on 50:1 oil mix.

We haven't ran it in water. We got it to start at the house and killed it right away so we didn't damage the engine.

That oil is extremely thin. It doesn't even come close to the thickness of the lower unit lube. The hole appears to be factory to me. Its a pretty clean hole.

I would not run no less than 32:1. 32 parts gas to 1 part oil.You will get more power(less frition,and less engine wear).The maunal probably say's
50:1,but they want you to buy a new engine after the warranty is over.
Now to get kinda techinical,the richer in oil, the leaner in fuel,so you may need to adjust the mixture screw on the carb.
My motocross bike calls for 40:1,but I run 20:1.I did have to rejet the carb,but I will get many times the life on the origional top end.
99% percent of the people you talk to will tell you to run 50:1,But,rememberThe oil in the fuel is what lubes the internals in your outboard,and gas don't lube too well.

I still stand by my original idea of 50:1. On the smaller ones (under 10 or so) I would go down to 40:1, as they still had bronze sleeve bearings. But, there should be no problem running this at 50:1. I definitely wouldn't go any more rich than 40:1 though. Fouled plugs will probably be a likelier event.