starts but wont run

[gclayton]

OK I again need the wisdom of the Afourian Gurus! Tried to start but bad gas in carb was the problem. Took carb apart and cleaned it. dumped old fuel, blew out fule lines, replaced gas water seperaator. With full choke and a bit of throtle it starts but wont let me decrease thre choke or it will stall. ran for about 15 min with throttle slowly increasing to about 25% and then the engine abruptly shut off. The idle screw is turned out 1 1/2 turns as recommended. Is it posibly running too rich and I need to close idle screw?

Any recommended fixes are appreciated.

Thanks all.

[Carl-T705]

If it will run with choke out and die with choke in, it is always too lean.
Me thinks you still have some trash clogging the main jet or the air bleeds and not sending the proper signal. Or..... a major air leak causing a excessive lean condition. It's very difficult to narrow it down any more than that. Hope this offers a little help,

[roadnsky]

George-
If you have to keep the choke engaged to keep her running, that spells LEAN instead of rich IMHO.

Maybe try turning the idle mixture screw IN (clockwise) a half turn. Wait 3 minutes...
See how it runs. If not better, another half turn. Wait 3 minutes...

Remember that the idle mixture adjusts the air portion of the mixture, so turning the adjustment IN makes the mixture RICHER, and backing it OUT makes it LEANER.
When engines stall while idling, it is usually because they are too lean.
How do your plugs look?

The fact that it shut down ABRUPTLY is a little strange though.
Was it really abrupt?
That points in other directions...

[Mo]

This easy stuff first:
- You might have an air leak in a line,
- filters have a direction of flow (usually an arrow on an in-line filter).
- check all clamps tight
- separator sealed good also?

Next..double check the carb. (If you had not been working on the lines I would have gone right here first).

-first try tightening the two bolts that hold it onto the manifold...sometimes an air leak there.
- if that doesn't fix it you need to remove and check gaskets on:
- manifold where the carb goes on
- remove the screws and separate the carb again...check that gasket then put it back together tight.

Sounds like sucking air issue to me. Do you happen to have a PCV kit...if so you can try turning the mixture screw in and see what happens. If you note a sheen on the water you know you are too rich.

My gut feeling is that there's an air leak in a carb gasket and might need tightening.

Hope that helps you out.

[tenders]

An abrupt death sounds to me like a cessation of fuel - an air leak is a potential cause; is the fuel pump itself fully up to snuff? My electrical pump died several years ago whereby it could supply enough fuel at low RPM but not at high RPM. The engine stumbled just a few seconds before dying, but if I caught it in the nick of time and slowed down it would be OK.

Another possibility: old coil. When it gets hot it stops working. In my experience this happens instantaneously, with no stumbling.

[Bold Rascal]

Been there....

Had the very same issues, Did a litle jiggling on the metal fuel line and found a major crack in it at the flared connection at the tank. Cut off old flare, purchased $50.00 flaring kit and 20 minutes later, runs great. Hope your problem is resolved as easy.

It's a great idea to rig up an outboard fuel tank with a good hose and priming bulb direct to your carb and start your trouble shooting from there.

[gclayton]

Great Advice I think ive got it

Everyone thanks for the advice and direction. Today I pulled the carb checked gasket, OK. tightened all connections, OK. Everything checked out. Started right up with full choke. Sounds GREAT except I still need full choke to keep her running. As suggested , turned idle jet in 1/2 turn, no help, another 1/2 turn, no help. Then I closed it completly, still no help but still running. So now Im at a loss. It obviously is getting air from some where. I reexamined everything and finally found the culprit (i think). I have a late model carb with a scavenge tube from the manifold to the carb behind the choke plate. Feeling around I discovered a small crack in the tube just below the fitting. I think this is where the air was being sucked in requireing excessive choke.

What say the Aforian panel of experts?

[edwardc]

Sounds like you may have it! In any event, you'll want to order a new scavenge tube.

Meanwhile, for a test if that's it, try removing the tube and temporarily sealing off the fittings at the carb & manifold. If that fixes it, you've got it!

If it still doesn't help, and you have a PCV valve, check that the same way as well. I recently had a PCV valve that wouldn't close properly, letting too much air in and causing the same symptom.

[gclayton]

not there yet

I tightened every connection, replaced the cracked scavenge tube but still cant get her to run without full choke. So if the choke makes the fuel richer could I possibly have a supply problem. Say a cloged jet (but I already cleaned the carb) I had some crap this spring not much but could I have a fuel pump clogged (new last fall)? Tomorrow I am pulling the whole fuel system and starting over. All help appreciated

Thanks
George

[JOHN COOKSON]

I tightened every connection, replaced the cracked scavenge tube but still cant get her to run without full choke. So if the choke makes the fuel richer could I possibly have a supply problem. Say a cloged jet (but I already cleaned the carb) I had some crap this spring not much but could I have a fuel pump clogged (new last fall)? Tomorrow I am pulling the whole fuel system and starting over. All help appreciated

Thanks
George

Been there done this. Triple check to see if the main jet is seated all the way. Also make sure your carb was assembled correctly when you rebuilt it. IMO this is most likely where the problem is.

TRUE GRIT

[roadnsky]

George-
Are you certain you turned the IDLE MIXTURE screw when setting the idle?
(See attached drawing)

Here are some pointers from Don regarding poor idle...

"CARBURETOR ISSUES AFFECTING IDLE:

1) Dirt in the idle jet.

2) A small speck of dirt in or near the upper of two tiny outlet ports of the idle system. This is the port (about the size of a fly speck) that you see just off the edge of the throttle valve when looking down from the mounting flange of the carburetor.

3) A faulty seal around the idle passage way between the upper and lower halves of the carburetor housing. This passageway is in the very center of the carburetor housing and is about the size of a drinking straw. If the gasket between the upper and lower housing is not completely sealed around this passageway, air can be drawn in and break the suction necessary to draw fuel up to the upper idle port.

4) A leaky float valve which provides such a rich mixture that it floods out the engine at idle RPM.

5) There is an air bleed hole in a small brass plug that is pressed into the lower face of the upper half of the carburetor that sometimes becomes blocked. This plug is located between the idle fuel jet and the venturi tube in the main throat of the carburetor and can be easily seen when the upper half of the carburetor is separated from the lower half. Sometimes a small speck of dirt lies on top of this small plug and interferes with the air being drawn in through the bleed hole to mix with the idle fuel."

In your case, numbers 1-3 bear checking out just as John suggested.

[gclayton]

John Jerry

Thanks for the help. I have a carb rebuild kit on hand so Ill start with that and rechecking the carb and cleaning and take it from there.

George

[gclayton]

half way there

So today I rebuilt the carb and she started right up cold full choke. Was able to open the choke back down and ran great at idle, throttle up in neutral and also under load ran for 5 min then shut down under power and or a idel. Immediatly with full choke started immediatly back up strong the ran a couple of min with choke or not and shut down like key was turned off. I then could start her Immediatly full choke then closed choke and run for a couple of min only to repeate fast shut down

Last fall new fuel pump, new coil, rebuilt carb (again today) engine ran but was just started after being seized. Now run GREAT but shuts down. I dont think coil could heat up in 5 min and shut down also it wouldnt start right up again. I didnt replace the inline fuel filter this spring but will tomorrow.

new fuel water seperator this spring next stop up is fuel pump new last year.

Wats my next move I have a new Facet fule pump last fall. Can they be cleaned or rebuilt to clear any crap.

It feel like I have full fuel then loose it, shuts down and then starts right up again sort of like something floats up clogs the line and floats back down after shut down only to float back up to reclog feul line.

HELP Team Aforian

George

[positron]

It sounds like the only thing you haven't replaced is the gas tank. Try hooking up an outboard gas tank with fresh clean gas to your fuel pump.

[gclayton]

My new gas tank isnt installed yet so i am using a new outboard tank and new gas.

I see there is a cap at the bottom of the fuel pump. Can it be cleaned, rebuilt ?