Sticking needle valve in closed position on a 25 HP Merc 1989.

[Garvdarb]

I have removed carb and cleaned it several times. It will start up and run. If I shut it off and it sits for a day and then try to prime the bulb it is hard as a rock, (new hose and primer bulb) I either have to stand on it or give the carb a rap with a small bar to dislodge needle valve. It will run perfect for a while, quit, choke it and it will fire up and do the same

 

[hotrod53]

I experienced the same with my 77 Thunderbolt 500. The ethanol in the fuel swells the tip of the needle valve. The new needles are ethanol compliment and are supposed to not do it. Personally I don't trust that it won't swell so here's the solution. At the end of each outing, disconnect your fuel line while it's running, raise up your enricher to a fast idle, let it run until it starts to sputter, then shut it off. This burns the fuel in the carb bowl and drops the needles. Boom.... problem solved! I shut it off as soon as it sputters knowing that the fuel has the lube in it so Indontbtun it completely out.

 

[Garvdarb]

I experienced the same with my 77 Thunderbolt 500. The ethanol in the fuel swells the tip of the needle valve. The new needles are ethanol compliment and are supposed to not do it. Personally I don't trust that it won't swell so here's the solution. At the end of each outing, disconnect your fuel line while it's running, raise up your enricher to a fast idle, let it run until it starts to sputter, then shut it off. This burns the fuel in the carb bowl and drops the needles. Boom.... problem solved! I shut it off as soon as it sputters knowing that the fuel has the lube in it so Indontbtun it completely out.

Thank you, I am having g success with that method. I was told by a small motor mechanic to add a bit of ATF fluid to fuel. I will try that as well. Do you think that possibly the float is out of adj. and that it is rising to high and forcing the valve up. It seems that if I am idling/trolling it will start to quit , I throttle up but it still quits. I choke it and away it goes for a bit.
Garv