proper fuel mixture for 1964 5.5 Evinrude

[jmk]

Hello all, jmk here. I bought a 1964 5.5 Evinrude last year. I am just getting it going. It came with a fuel tank which he said was fresh gas last year. He had wrote 25 to one on the tank. This seems to me to be a lot of oil. Does anyone know the proper fuel mixture? It seems to me that most motors are 50 to one. My sevice manual says to check the owners manual, and I don't have one. Thanks, jmk.

 

[crappiejig]

Re: proper fuel mixture for 1964 5.5 Evinrude

My 1963 johnson 10hp needs 24 to 1. I believe there is a sticky here on the forum that pretty much covers all the outboards. Just poke around the forum I am sure you will find it.

 

[82mustang]

Re: proper fuel mixture for 1964 5.5 Evinrude

Hot topic on mix ratios. Heres what I've heard from a several people.

1) Newer oil provides way better protection than it did back in the 50's and 60's, so 50:1 would be ok

2) Here on I-Boats forums, the marina mechanics always say 25:1 because thats what the internal componts (bearing, seals, etc) were desnged for.

I have the same motor, 2 of'em actually, and run 50:1 without a problem. I originally did 25:1, and it smoked so bad, I was getting allot of dirty looks from others on the water. Advantage to more oil is you know you won't sieze the motor. Disadvantage, allot of smoke, and more frequest plug changes (there cheap anyway, but still) and you will require to decarb way more often I would think.

With all that being said, up to you. I'd be tempted to do like 40:1.

 

[bktheking]

Re: proper fuel mixture for 1964 5.5 Evinrude

In 64 they changed to 50:1, that motor stayed 24:1.

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

Yes I have checked the compression. Both cylenders are getting 80 lbs. I don't know what they are suposed to be though. I was thinking 80 for those little buggers would be about right, but I forgot to check what they are suposed to be so I am glad you asked. Do you know what they are suposed to be at?

 

[bktheking]

Re: proper fuel mixture for 1964 5.5 Evinrude

Cool, should run fine @ 80, it's part of my signature now cause so many people don't "check compression" and wonder why their motor won't fire

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

Thanks, That's great! I have gone through the lower end, carburetor, leaf valves, and fuel pump. The motor runs and starts, but doesn't like to idle at the shift mark. When adjusting the mixture screw it runs smoothest almost all the way closed, but I am not sure if I have the rpm right. Anyway, my problem now is it bogs when I run it up. I havent yet got into the flywheel to look at the points. I am hoping that they need some tuning. I will have to check the advance timing too. I put it on my boat because it seemed to be running good, but when I gave it gas it didn't go faster. In fact it started to act like it was heating up. I am not the best at the electrical, so I always hope it is at it's peak performance when tuning. I guess I will get in there and read and read the book, and press on. Maybe I can get a friend to help with that part too.

 

[bktheking]

Re: proper fuel mixture for 1964 5.5 Evinrude

When you had the carb apart did you clean out orifice in the carb bowl? Did you put in a carb kit or just clean it?

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

One other thing that I wanted to say is that it came with new fuel lines with spring clamps. I want to change those out with hose clamps because I want to make sure it isn't leaking. The glass filter bowl goes empty to half full of fuel when operating too. It seems to me that it should be full all the time. Do you know if it is suposed to fluctuate like that? I may be starving for fuel when I get it reved up because it's sucking air is another thing that I was thinking. I was going to change the clamps first and see if that makes a difference. The guy I bought it from actually changed the fuel pump. It does pump fuel too.

 

[bktheking]

Re: proper fuel mixture for 1964 5.5 Evinrude

Has it got a sintered filter in it, as the metal round ones, in the glass bowl?

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

I put a new rebuild kit and float in it. I drilled the plug out and sprayed the inside of it with carburetor cleaner. Really the only part that looked dirty was where the needle valve seat was stuck with a white foamy substance. The rest of the carburetor didn't have varnish hardly at all. He said he ran sea foam in it when he put it away. I was wondering if that might have foamed the varnish in the needle valve to the point of glueing it closed. This was the initial problem when I bought it. I thought that it was stuck and it was, but now I am haveing more problems than that. I did take the carb apart again to clean it one more time but I didn't mess with that plug the second time.

 

[bktheking]

Re: proper fuel mixture for 1964 5.5 Evinrude

Just looked at the diagram, looks like a paper type filter. Pull it off if it's there and retest. What if you pump the bulb to try and fill it up while it's running?

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

Yes, and I replaced that too along with the gasket that the bowl seats against

 

[bktheking]

Re: proper fuel mixture for 1964 5.5 Evinrude

I put a new rebuild kit and float in it. I drilled the plug out and sprayed the inside of it with carburetor cleaner. Really the only part that looked dirty was where the needle valve seat was stuck with a white foamy substance. The rest of the carburetor didn't have varnish hardly at all. He said he ran sea foam in it when he put it away. I was wondering if that might have foamed the varnish in the needle valve to the point of glueing it closed. This was the initial problem when I bought it. I thought that it was stuck and it was, but now I am haveing more problems than that. I did take the carb apart again to clean it one more time but I didn't mess with that plug the second time.

The fuel bowl has an orifice behind a screw, the plug I hope you drilled out was at the top of the carb, welch plug to be exact. That orifice needs to be clean.

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

Ya that filter looks like paper but it's plastic, at least mine old one was and the new one. I did pump the bulb and it does fill the bowl while runing. I didn't pump it while opening the throttle up. I could try that. When I pump it it fills the bowl then the engine takes it back down. It runs in gear at the start possition with the gas gone in that bowl which made me think the gas was looping above the bowl, but it made me wonder.

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

The fuel bowl has an orifice behind a screw, the plug I hope you drilled out was at the top of the carb, welch plug to be exact. That orifice needs to be clean.

Yes, the welch plug is what I drilled out to clean the oriface. It actually looked clean and I could see fluid getting through the little holes. It's a little lead disk that has to be peened back in.

 

[bktheking]

Re: proper fuel mixture for 1964 5.5 Evinrude

This is what I am referring to:

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

I pulled that screw out and sprayed in there, but I didn't know there was another plug - screw inside there. Part # 56 I didn't take that out.

 

[jmk]

Re: proper fuel mixture for 1964 5.5 Evinrude

Looking at that diagram I'm not sure that I changed the ring part 61 either. I tightened the main jet just snug.

 

[bktheking]

Re: proper fuel mixture for 1964 5.5 Evinrude

#66 yes, that's the orifice, just make sure it's clean. # 60 as well, high speed nozzle, very tricky part. This one was the low speed on my Merc KH7, it had a grain of sand in the nozzle, completely messed up my low speed idle. You should be able to blow in it and have air come out the holes, if it's hard to blow into it's plugged up. You say you don't have high speed and gas isn't filling up the bowl, could be the issue.