1983 25hp Evinrude running rough

rpena · Nov 29, 2011

Hello Im hoping someone can help me figure out what's wrong with my Evinrude outboard. It sat for 4 years, so I put a carb kit on it, a fuel pump kit, new fuel lines. It starts right away idles good for a short while then starts to sputter and dies. Does anyone have any ideas?

richg99 · Nov 29, 2011

I know that I would first check the fuel tank air vent. If it is closed, you will create a vacuum after a short time running. That vacuum will shut down the fuel flow and the motor will stutter and stop. R

rpena · Nov 29, 2011

Thanks !! I'll check that first thing Thursday when I get back to it.

rpena · Nov 29, 2011

I just checked the gas tank, I still had it hooked up from earlier when I tried it but the vent was open. Could it be the fuel pump? just before starting it I found the fuel pump leaking where the fuel line goes into the fuel pump used another gasket and it stopped leaking, but maybe that's whats causing it?

jasper60103 · Nov 30, 2011

rpena said:
I just checked the gas tank, I still had it hooked up from earlier when I tried it but the vent was open. Could it be the fuel pump? just before starting it I found the fuel pump leaking where the fuel line goes into the fuel pump used another gasket and it stopped leaking, but maybe that's whats causing it?

That could be it. If that doesn't solve your problem, try pumping the bulb and see if the problem goes away. That could indicate a faulty fuel pump. Since it setup for a while, I'm thinking the fuel filter screen (#3) may be gummed-up. I would take a look...

https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1983&hp=25&model=J25RCTE&manufacturer=Johnson&section=Fuel+Pump

richg99 · Nov 30, 2011

Well, I am no mechanic. Any air leak, anywhere in the tank/fuel/line system could cause it to stutter and go out. The air leak causes it to lose its suction.

The new ethanol gas can cause the INSIDE of fuel lines to deteriorate. I had to replace my bulb and line after I started using more ethanol gasoline.

When it starts to stutter...if you press on the bulb...does that smooth it out? R

rpena · Nov 30, 2011

The leak was right at the pump where the filter #4 attaches to the pump #1 when I took it apart it only had one gasket #2, so I used 2 of those gaskets to get to stop leaking.

I checked that screen and it was clean.

richg99 · Nov 30, 2011

Good for you! Nice sleuthing.. R

rpena · Dec 2, 2011

Thanks! Well I was messing with it last night and it will run on idle semi smooth, but only with full choke on. I removed the filter cap cover and i'm going to replace it I think it might have an air leak somewhere around that filter cap. Hope tha's it.

rpena · Dec 2, 2011

This was the only gasket present when I took it apart the first time. I used to two to keep it from squirting out fuel. However I just got home with some parts and it seems, there are two o-ring gaskets that were'nt present when I took it apart. hope this will do it.

Pappy · Dec 2, 2011

Don't waste your time. That will not be your problem. The sole purpose of the pump is to fill the carb bowl and keep the needle and seat in the carb closed. If your carb is being filled with fuel, either with you squeezing the primer bulb or the fuel pump is supplying enough fuel then the issue is probably in your carb. Lets say you have a minor air leak in the pump but it is still enough to supply fuel to the engine to run. Any air supplied will simply vent out of the bowl, leaving only fuel/oil. You can find any air leak in that pump by applying pressure with the primer bulb. Your "air leak" will turn into a visible fuel leak.

Captain Ahab · Dec 2, 2011

Pappy said:
Don't waste your time. That will not be your problem. The sole purpose of the pump is to fill the carb bowl and keep the needle and seat in the carb closed. If your carb is being filled with fuel, either with you squeezing the primer bulb or the fuel pump is supplying enough fuel then the issue is probably in your carb. Lets say you have a minor air leak in the pump but it is still enough to supply fuel to the engine to run. Any air supplied will simply vent out of the bowl, leaving only fuel/oil. You can find any air leak in that pump by applying pressure with the primer bulb. Your "air leak" will turn into a visible fuel leak.

Exactly!

You have a leak in your fuel line - most likely one of the connections - tighten them up a little and you will be fine

rpena · Dec 2, 2011

Thanks for the info guys, I will look for that air leak tomorrow. When I was changing out the old fuel lines I replaced a small diameter hose that went from one part of the block to the other like a vacuum line, cause it looked old and brittle. After I put everything back together I found another one just like it, but left I was out of hose. Could that possibly be part of the problem, does that have anything to do with carb?

rpena · Dec 3, 2011

Well I went out and bought a new OEM hose that goes from the tank to the engine, but ran the same only with full choke. I'm take it apart now to demean the carb and check all the fuel lines.

Pappy · Dec 4, 2011

I don't think you understand yet! You can look for as many air leaks in fuel lines as you want to and it will be a waste of time. If the engine runs while the choke is on then the issue is more than likely in your carb.

rpena · Dec 4, 2011

Thanks, I removed the carburetor last night going over it again. I placed it in a ultra-sonic clear and noticed some debri come out of the bowl area scrubbed it again and then rechecked it. I'll install it Monday and hope this does it. I'm so ready to get out on lake!

rpena · Dec 4, 2011

I forgot to mention that when I tried to shut the engine off with the key it would not shut off, I tried the emergency shut off switch and still nothing...?

rpena · Dec 23, 2011

Well, got the Rude Running! It's Alive!! It's aliiiive!!!!! The second time I cleaned it I found some trash in the jet that's in the bowl. When it started it ran for short while then shut off, then I realized that I needed to open up the low idle adjust screw. It's running great! All I need now is a nice day to go to the lake. Thanks for help guys!

jasper60103 · Dec 24, 2011

Good to hear. Hope the lake test goes well.

richg99 · Dec 25, 2011

Great news. Glad you found the problem. Funny how a little "something" can mess up your day and your fishing trip.

re "need a nice day"....Heck, A nice day in North Texas might be next week. In some parts of the country..it might be five months! Ha ha

46 degrees here on Christmas morning and rainy.
Bah humbug... Brrrr......

regards, R

1983 25hp Evinrude running rough

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