1972 Evinrude 40 HP fuel problem

[Bigboyitm]

I am borrowing a boat from my boss this weekend and thinking about buying it from him. It hasn't been ran in 2 years according to him. Well I got it home today and put my fuel tank on it with fresh gas and it started up and ran for a few minutes, but it was pouring fuel out of the over flow hole. My boss told me that the carb needed cleaned out before I took it out in the water, so I took it off the motor and tore it down and cleaned everything up. Now the issue is it isn't getting any fuel out of the carb. I can spray fuel into the carb and it starts up but dies as soon as that fuel is gone. Please someone help!

 

[tx1961whaler]

Re: 1972 Evinrude 40 HP fuel problem

There is a problem with the carb Float/needle. First it was stuck open, now it's stuck closed.
The carb really needs to be thoroughly cleaned (disassembled, soaked in solvent, passages shot through with carb cleaner, blown through with compressed air, etc.) and a rebuild kit with new gaskets and parts installed.

 

[Bigboyitm]

Re: 1972 Evinrude 40 HP fuel problem

Well if I need a carb kit for it I guess it won't be in the water this weekend. I did disassemble it cleaned it well with carb cleaner and blow it out with compressed air. I'm gonna pull it back down in the morning and check the float out, it has spring attached to the needle itself but I'm not sure where that hooked around. I have it around the shaft to the float, that could be putting it in a bind not letting it fall when the float falls. I'm gonna just take the spring out and see what happens. Thanks for the help! If what I think it might be doesn't work then it will be getting a kit soon.

 

[lindy46]

Re: 1972 Evinrude 40 HP fuel problem

The spring does attach to the float arm. You can see if it's working properly by moving the float up and down. The spring should pull the needle up and down with the float with no binding. With the carb upside down, float should be almost parallel with the carb body. I usually bend the arm ever-so-slightly up so the float is a little bit higher than parallel (when the carb is upside down). Once you put the carb back together, blow in the gas inlet with the carb right-side-up, and air should pass. Turn the carb upside down and blow again - no air should pass.

 

[Bigboyitm]

Re: 1972 Evinrude 40 HP fuel problem

Well I saw this morning that the spring did need to be there. If I wind up buying the boat from him I will be getting a carb kit for it and redoing it. I believe that the float and everything in the carb is working well but the fuel pump is not working. The reason I say that is because I can spray fuel in the carb and it will start and I can take the primer bulb and pump it and keep it running for a few and then I can't pump fast enough.

 

[Bigboyitm]

Re: 1972 Evinrude 40 HP fuel problem

I have a question. On the top of the carb there is a low/high speed adjustment screw. How much from bottomed out do you turn that screw out before fine tuning it? And could this be part of my not getting enough gas to start? I thought I read somewhere that 2 1/2 turn and then let it warm up before adjusting.

 

[lindy46]

Re: 1972 Evinrude 40 HP fuel problem

That needle should be 1.5 turns out to start. If you pump the fuel line bulb and thre motor keeps running, but dies when you stop pumping, you have a fuel pump problem.

 

[Bigboyitm]

Re: 1972 Evinrude 40 HP fuel problem

That's kinda what I've been leaning towards. I plan on ordering a rebuild kit for it soon so I can get it going.

 

[Bigboyitm]

Re: 1972 Evinrude 40 HP fuel problem

Well I finally ordered the carb kit and rebuilt the carb. It starts and stays running now. I think it has a timing issue now, because when you throttle it up and then back down most of the time the throttle sticks. If you turn the ignition off and then back on real quick it goes back to idle. What are y'alls thoughts on this I have no clue.

 

[tx1961whaler]

Re: 1972 Evinrude 40 HP fuel problem

Watch the magneto plate rotate when you throttle up and down. Also watch the little cam roller that rides on the plate to make sure it is closing. The cam follower is spring loaded to keep it closed when you pull the throttle down.

 

[Bigboyitm]

Re: 1972 Evinrude 40 HP fuel problem

I'll check that out monday and see whats going on there. Thanks for the advice.

 

[lindy46]

Re: 1972 Evinrude 40 HP fuel problem

That cam follower actually pushes away from the cam when you run WOT - there is a rod on the port side of the motor which controls it. May be sticking and not returning to the cam when you move the throttle to slow.

 

[Bigboyitm]

Re: 1972 Evinrude 40 HP fuel problem

The cam follower is working like it should. I have no clue what to look at now, I don't have a book on the motor yet and this is the first boat motor I've ever worked on. I'm new to boats but not mechanics, so I'm sure with a little help I will be able to get it going soon.