What mixture for an outboard boat motor

[Hale on wheels]

Does anyone know offhand what mixture an old Johnson outboard motor is supposed to run? 16:1? I don't remember, and I don't want to run the gas mix that is 6 years old in my tank through the motor! Thanks for the help.



Cody

 

[LSMITH]

All of the newer ones run 50:1. They recommend 30:1 for breakin, then 50:1. I don't remember ever seeing a 2 stroke that ran richer than 30:1, but I could be wrong.



How old is the motor? HP rating? Is there a model #? With a little more info someone here will be able to say for sure.

 

[Champane Flight]

Old too

I have a 70-85hp Johnson that runs 50:1 .

 

[gitchesum]

My 84 model Johnson 90 hp V-4 runs a 50:1 mixture

 

[Hale on wheels]

It is an early 70's model 10hp for my duck boat. I would imagine it would be 50:1 like all the others as well, so thanks for the info guys.

 

[LSMITH]

I had a 95 model 4 horse that was 50-1, and now have an 01 model 25 horse that is 50-1. If you wanted to be very safe they run fine at 40-1 too, low speeds for a long time will foul the plug a tad but a good WOT run will clean it up.

 

[Hale on wheels]

Well I am usually running slow speeds (like a 10hp will go fast anyway) through stumps and underwater cover, so I will try 50:1 so as not to foul the plugs. I actually could not get it started though. It will run when I pour fuel through the carburetor, but it won't suck fuel from the tank. I thought I had cleaned the carb out good, and I got some gummed up crud out of it, but I guess not good enough. When I went to college, I didn't hunt for about 3 years, so my boat was sitting up that long, and now it won't run. I actually had to pour some marvel mystery oil in the spark plug hole to free up the pistons, so I imagine the motor is in pretty rough shape. The boat place in Plano won't work on it because he says it is too old, and another guy said he would work on it, but it was going to cost me around $250-300 to get it running. I don't think the whole motor is worth that, so I may just look for a 15-25 hp motor anyway.

 

[BV]

gas/oil ratio

It should be 50:1 - In the early 90's I had a 6hp Johnson that was broke in with 50:1 then ran on 100:1. My Homelite chainsaw is suppose to use 16:1 but has run just fine for 10 years at 40:1.



IMHO - The amount of oil is not as important as the quality of gas and oil as well as setting the low and high jets on the carb.

 

[The patriot]

Hale on wheels, an old commercial fishermans trick:

Pull the plug and heat it up with a match or torch. It'll be much easier to start.

Eric

 

[Hale on wheels]

Thanks for the tip, but I don't think it is getting any fuel Eric. If I pour some gas down the top of the carb, I can pull and it will fire and run for a second until it burns up the fuel, and I can keep it running by pouring more fuel in. I cannot get it to run on its own however. The carb or something is still clogged somewhere. It will fill the float bowl up with gas, so it has to be in the top side of the carb (or so I thought). The jets are set in with a lead plug that I don't want to drill through because I don't have any way to refill it.

 

[Hale on wheels]

Well after a lot of cranking I got it to run for a few seconds at a time. It will not run continuously though. Since it does run, I guess the carb isn't clogged after all? I don't know why it won't keep going though. Have to try to figure that out tomorrow.

 

[Champane Flight]

Fuel lines

Check your fuel lines, make sure you have no cracks, holes or loss of prime. If your fuel bulb is pumping fuel up to the carb, it should not lose prime. Look for any inline filters or a strainer on the engine and check those.