No Fuel going into Carburetor Bowls 2000 50 hp

[McFlounder]

I pump primer bulb and fuel seems to flow fine. Fuel shoots out when fuel line removed from top carb and squeeze bulb used and also from VRO pump when cranked by starter. No fuel appears to be in either bowl when drained, not a drop comes out of either drain hole. It had only been a week since the engine last ran. Fresh non ethanol fuel. Same thing with portable tank and built in tank. New fuel lines. Carbs have only about 5 hours use since both carbs last rebuilt about 2 years ago. Any ideas? Could it possibly be needle and seat? This one is really getting to me.

 

[jbjennings]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

If the fuel line going to the carb is pulsing fuel and there's nothing in the bowl, I would thing it must be the needle and seat. The neoprene tip of those darned needles is terrible about sticking. The 5 hrs. of use in 2 years is probably the reason. Sitting without having fuel run past the needle makes it stick. My 90hp Yamaha did it this spring after sitting idle for about 3 months. I would just replace the needle and seat if there's a groove in the neoprene, or if the neoprene tip tears when you try to remove it, or just replace it because it's probably the right thing to do. It is really odd to me that they both stuck at once.... I'm thinking the bowl on the top carb has a nipple that lets fuel into the bottom carb??? So if the top needle sticks, both carbs don't get fuel???
GOod luck,
JBJ

 

[McFlounder]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

Thanks for your reply. Actually there are 2 seperate feeds, one into each carb. The lower carb is hard to get to so I haven't disconnectedthe fuel line to it yet. The 5 hours are because of shoulder surgery 2 years ago, but I have started the engine regularly (about 10 minutes a week) at idle with flushing device and have had fresh ( not more than 2 months old) non ethanol fuel at all times. Usually, I disconnect line and run fuel out of carb as much as possible. Even after doing this, there is fuel flow out when drain screws opened on each carb, although I haven't been doing this lately since I now start engine every weekend. You are probably right about needle seat, but would this prevent any fuel from entering either carb and its odd that both carbs would hppen at the same time? I am just hoping that I am overlooking something too obvius too see. Any input is welcome.

 

[glenn property of pam]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

sounds like stuck float needles like jbjennings said. Also its not a good idea to run a 2 stoke out of gas its better to add fuel stabilizer and leave the carb's full or drain them by the screws. If you are running every week or two then leaving full is fine.

 

[McFlounder]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

Thanks for your input. Looks as though I'll be tearing carbs off this weekend, weather and honeydo lists permitting. Oil line doesn't get disconnected, so really never thought of running carbs empty as harmful. It still seems odd that both carbs would go at same time, but I can't think of anything else either. I'll report back here once I have a look insde. Thanks again

 

[McFlounder]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

Tore carbs apart this weekend. Needles and seats stuck closed as you guys projected. Freed up and soaked carbs before reinstalling. I found some black residue in both carbs, not much, but it apparently take much. It looked like rubber or plactic and felt soft to the touch. Since there are no signs of this in inline sigh filter I suspect they are coming after the filter. This would suggest oil from VRO system, the oil line or the VRO pump itself. I checked oil reservoir with turkey baster and it was clean. I will probably chane the oil line next weekend even tough it looks good. Anyone want to venture insight or guesses here?

 

[McFlounder]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

Oil and system appeared very good. I started pulling some other stuff off including fuel filter. When dumped into a bowl, the gas appeared to have fine rust in it. A close inspection of the filter showed the bottom of fuel filter canister was rusting. Maybe this is the proplem. Running off portable tank with no connection to filter, engine started and ran flawlessly on flushing device. New filer(s) time.

 

[tomwsk]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

Looks like you've solved your problem. Good for you.

 

[Cal-MI]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

Needles and seats stuck closed as you guys projected. Freed up and soaked carbs before reinstalling. I found some black residue in both carbs, not much, but it apparently take much. Anyone want to venture insight or guesses here?

We have had a rash of stuck needles at the marina where I work this year. Johnson, Mercs, other brands. We are guessing it is the ethanol in the fuel. The gas station pumps apparently no longer notify you if they have ethanol in the fuel. Anyway, the fuel lines in pre 2000 motors are attacked and deteriorate. You sometimes get black gum that even passes through the fuel filters, it is so fine. And neoprene-tipped needles on an old 6 hp Johnson, for example, have to be blasted open with a jet of air after the engine has sat overnight.

Of course, we put marine grade ethanol smart Sta-bil in the fuel. Our next step will be to replace all fuel lines with ones that can handle the e-gas without breaking down. It should be labeled SAE J1527 Type A1-15. And maybe then, hopefully, replace needles with new ones who's tips will not get gummy. Of course, we run the risk of getting old stock needles that are not alcohol resistant.

FWIW I had a Merc fuel filter gasket last year that had swelled to oversize and would not re-install. I replaced it with a newly-purchased one, and the new one swelled to oversize overnight. It could have been old stock, or maybe was made of inferior material to begin with.

 

[McFlounder]

Re: No Fuel going into Carburetor Bowls 2000 50 hp

Thanks for your input! I have been running engine everyday from portable tank as I have not yet replaced water/ fuel seperator filter yet. Though I did find a minute amout of black residue in carbs, the fuel in canister had a very fine rust in it. This is curious since I had the under floor tank pumped "clean" and have used "ethanol free" gas since. The pump at Marathon is clearely marked no ethanol and they charge plenty for it. I have been gradually pumping fuel out of under floor tank out using a squeeze ball and through a cloth filter into a clear container and it appears very clean, not a spec noted, nor any signs of water. All fuel lines have been replaced, I now see that I was sold a vacuum line for the small primer hoses that go to tops of carbs. I will replace those. All said, I currently believe the problem stems from the rusty water/fuel seperator. I will report back with any further details as they occur.