40hp Evinrude will not stay running

[Wayne.Walker]

I have a 1986 Evinrude 40hp outboard that will not stay running. I put it the lake to test it last Sat and it stalled, bucked, etc. I came home and started reading this forum. Decided to rebuild the carbs and replace the leaky service valve (which I believe is in/on the choke) and install a new fuel line vent; because the NEW tank I bought didn't come with a vent. After all that, it sarted right up, but will not run but a few mins. As I said, the carbs are rebuilt, new service valve, new tank with new fuel ball and in-line vent valve, with new hoses. I pump the ball about 6-10 times, and start it up, watch the fuel in the filter ( looks to stay the same) and after a few mins, it dies out. Pump the ball 6-10 times and it starts back up and runs again for a few mins, then dies! I am perplexed to say the least. I'm a car guy, not an outboard guy, so I need help as I am at the end of my rope. I think it has a fuel pump on the right side of the carbs (as looking from bow to stern) it is a black housing that the main fuel line runs to, but not sure. The main fuel line comes in from the filter, then into the bottom of that black housing, then exits out of the top and appears to feed three lines; one to the top carb, one to the bottom carb, and one that "I THINK" runs to the choke or whatever that thing is that houses the red service valve. Any help is very much appreciated. I added as much info as I could and know. Thanks,

Wayne

 

[SparkieBoat]

fuel pump bad?

 

[gm280]

Sounds like it is running out of fuel. So either your tank is not allowing fuel to continually flow, or your fuel pump isn't pumping the fuel to the carb. Try opening the fuel tank's gas cap to see if it stays running because you mentioned that you had to re-prime the fuel priming bulb after it shut off. And that indicates the tank not flowing fuel... JMHO!

 

[Wayne.Walker]

fuel pump bad?

Not sure. Not sure if it has a fuel pump. As I wrote, it has this black housing beside the cabs that the fuel line comes into and appears to come out of and go go the carbs, but it is rather large and shaped like it has a "vane" inside. Hard to explain in text. I looked up the "fuel pump" on-line and it is just a small little piece and I don't see anything on my motor that looks like the pictures of a fuel pump.

 

[Wayne.Walker]

Here is a pic of that black housing beside the carbs.

 

[Wayne.Walker]

Trying to load a pic

 

[gm280]

Not sure. Not sure if it has a fuel pump. As I wrote, it has this black housing beside the cabs that the fuel line comes into and appears to come out of and go go the carbs, but it is rather large and shaped like it has a "vane" inside. Hard to explain in text. I looked up the "fuel pump" on-line and it is just a small little piece and I don't see anything on my motor that looks like the pictures of a fuel pump.

Fuel pumps on OB engines are usually a diaphragm type material that uses little one way valves to suck the fuel in and then pressurize it to push it to the carb. So they can look flat and work great. The engine crankcase supplies the pulses to operate the fuel pumps most of the time. Just some info for you...

This is what you should be looking for as a fuel pump on your engine:

 

[Wayne.Walker]

Thanks gm280. Unfortunately this may end up in the hands of a pro

 

[racerone]

It certainly has a fuel pump !!-----That automatic oil mixing pump can also be used as a pump only for mixed fuel.----Have you confimed if the VRO unit is in fact in service and working properly??-----Report the results of a compression test on that motor.

 

[Wayne.Walker]

Thanks for the pic gm280, I cannot find anything on my motor that looks like that! I looked on the right and left sides of the carbs and see nothing like it. I and starting to think that I have a VRO system (that weird black housing next to the carbs with fuel lines going in and out), but know nothing about it. People are all over iboats Forum talking about "bypassing" the VRO and bla bla, but it is all Greek to me. If I have a VRO, shouldn't I have an oil tank? I traded for the boat a few months ago and do not know any history and the guy I got it from is not helpful.

 

[Wayne.Walker]

racerone, it runs great as long as gas gets to the carbs the compression on each cyl is 125. She's tight, just needs fuel and I think I may need to bypass the vro, if in fact I have a vro system on it. It's driving me crazy!

 

[gm280]

Thanks for the pic gm280, I cannot find anything on my motor that looks like that! I looked on the right and left sides of the carbs and see nothing like it. I and starting to think that I have a VRO system (that weird black housing next to the carbs with fuel lines going in and out), but know nothing about it. People are all over iboats Forum talking about "bypassing" the VRO and bla bla, but it is all Greek to me. If I have a VRO, shouldn't I have an oil tank? I traded for the boat a few months ago and do not know any history and the guy I got it from is not helpful.

Wayne, take your model number and year of manufacture and search the net for your engine break down. It will show you what everything is and where things like the fuel pump "Should" be located. However, being it is used to you from who knows who, there is a possibility that it was modified and therefore can be missing things of importance. However, before using it too much, verify that it is indeed using 50:1 fuel mixture (if there is no VRO setup) to be safe... In other words use pre-mix in your tank if you have any doubts. JMHO!

 

[Wayne.Walker]

JMHO, I will certainly look for that right after I send this out. Update: apart from me NOT knowing really anything about outboards, I did find out the following: it does have a VRO (that black housing next to the carbs), it HAS already been unplugged and the oil line blocked off. With that said, now that I know that the VRO on it has been bypassed, what will cause it to run out of fuel without constant bulb pumping? Is the fuel pump inside the VRO? Or do I need to buy a regular fuel pump and just mount it somewhere?

You guys have been great on here, I really appreciate your help!

 

[Wayne.Walker]

Caddis295, I am having a similar issue after rebuilding carbs, new tank, new lines, ect. I just discovered that I have a VRO, but the previous owner unplugged it and plugged off the oil line. So my question is: can I just buy a fuel pump (2 line model) and mount it on the side of my engine like in the pic above, or ??? By the way, mine is a 86 40hp Evinrude that runs great as long as you sit in the back and pump the ball.

 

[GA_Boater]

Caddis295, I am having a similar issue after rebuilding carbs, new tank, new lines, ect. I just discovered that I have a VRO, but the previous owner unplugged it and plugged off the oil line. So my question is: can I just buy a fuel pump (2 line model) and mount it on the side of my engine like in the pic above, or ??? By the way, mine is a 86 40hp Evinrude that runs great as long as you sit in the back and pump the ball.

Moved your old thread hijack into your current thread. Please look at the Help Tips on top of the page. How to attach pictures.

 

[Wayne.Walker]

OK, I bent over and yelled, " Pop and flutter" ( its an ole' Navy Diver term for pulling your head out of your ...) and figured out my issue! Thank you all so much for your help!!! I DID have a VRO system, it WAS bypassed, I did NOT have a fuel pump, but now, I DO have a new 2port fuel pump with all lines ran and she runs like a champ! I would have probably never figured it out on my own, thank God for a place like this to ask for and exchange ideas with people that have the knowledge to pass on. Thank you all very much. Now, my son and I are truly ready for Duck season!

 

[pro-crastinator]

Love it when a plan comes together...........