1963 Johnson 75 horse...cant keep running possible fuel problem

[Trailryder927]

Hey everyone. I am new to this site as well as boating so please forgive my ignorance on all of this.

I bought a 17 foot renken boat. It has a 1963 75 horse Johnson electramatic. We had the boat running pretty well, but when it came to show time it wouldn't stay running. When I started in the water for the first time...it would run...but wide open. That was with the start lever down...which after I looked closely...it slightly advances or retards the timing...(i think). Then it just died. I do have spark. It will also run under ether. And I pulled the hose going to the back of the two carbs and I had fuel up to that point. But, I pull the plugs and none of them are wet, or smell like fuel or anything. Im also getting fuel out of the exhaust from what i can tell. I don't know if it's not getting constant pressure? The fuel line going to the carbs is attached to a pump. It's a fuel in, fuel out deal with a glass bowl and filter. I cleaned that. It also has another hose that I'm going to assume is vacuum. That operates a little diaphragm / pump thing. There are two long adjustment screws in front of the carbs. I pulled them out and they are 2.5 to 3 inches long. From what i can gather...they seem like an air fuel mixture. From what im told they adjust it rich and lean. I tried tweaking those as well. So from what I can tell I'm not getting fuel from the carbs, to the cylinders. Any help would be greatly appreciated.

[EricJRW]

Your problem sounds much like mine (I omitted my original symptoms, but they are the same as yours). You may want to check out my "ethanol rears its ugly head" thread (http://forums.iboats.com/johnson-evinrude-outboards/1993-50hp-evinrude-outboard-ethanol-has-reared-its-ugly-head-550543.html), as that's what I'm chasing.

When you pulled the fuel lines to the carb(s) and checked for fuel did you notice any black gunk in the gas?

Also, I'm not sure what you meant by "It will also run under ether."

[Trailryder927]

Your problem sounds much like mine (I omitted my original symptoms, but they are the same as yours). You may want to check out my "ethanol rears its ugly head" thread (http://forums.iboats.com/johnson-evinrude-outboards/1993-50hp-evinrude-outboard-ethanol-has-reared-its-ugly-head-550543.html), as that's what I'm chasing.

When you pulled the fuel lines to the carb(s) and checked for fuel did you notice any black gunk in the gas?

Also, I'm not sure what you meant by "It will also run under ether."

What i meant is it runs with starting fluid now. Just not under its own fuel. I did use that startron stuff in my fuel. But I also just bought this thing. And ALL of the lines are spongey. I replaced my primer fuel line going up to the engine, along with the fuel quick connect thing.

[EricJRW]

Yeah, I did that too... But only after realized I got lots of blank gunk. I'm sure it's fouled my carbs, and since I'm thinking carbs will be need to be cleaned, I'm going to replace all the remaining fuel lines too... And now it sounds like the diaphram in the fuel pump too.

Oh, did you happen to try the "pump the primer bulb while the engine is running" trick? If that works, then the fuel pump is more likely the culprit.

[Will Bark]

Don't use ether starting fluid; there is no oil in it to lube the engine and you can ruin it. Spray premix in the carbs to try to start it instead.

[Trailryder927]

Yeah, I did that too... But only after realized I got lots of blank gunk. I'm sure it's fouled my carbs, and since I'm thinking carbs will be need to be cleaned, I'm going to replace all the remaining fuel lines too... And now it sounds like the diaphram in the fuel pump too.

Oh, did you happen to try the "pump the primer bulb while the engine is running" trick? If that works, then the fuel pump is more likely the culprit.

I did try that, yet it didnt seem to make a difference. i took the pump off when i cleaned the bowl...and i sucked and blew into that tube and the diaphragm opened and closed. I dont know how well of a test that is.

Is the fuel level in the bowl supposed to be at a constant?

Also, if im getting fuel up to the carbs..but fuel isnt getting to the cylinders... what can cause that? Dirty carb? Needle and seat?

[63Sport16]

If you are certain the fuel pump is working and fuel is getting to the carb, then the next step would be to clean the carb thoroughly. I've also got a 63 75hp. it's got a single float to feed the entire motor so if the needle and seat have an issue there is either way to much fuel to all 4 cylinders, or, little to no fuel to all four cylinders.
Be sure to look for pieces of rotten hose in the passages and blow them out good. I'd just make it a rebuild myself so I knew I got a clean carb.