470 2b carb flooding/starvation problems

[natemoore]

Uh...is it normal to see gas dripping down from the venturi into the intake manifold just after the engine is shut off? I'm thinking not.

I double-checked the float level and float drop settings, then blew into the fuel inlet side of the float chamber to verify that the valve would shut off fluid flow. All seemed okay.

The engine would run like a top for a few minutes then just die. I am fighting a bent pushrod problem which could cause the dying, but the fuel dripping into the intake manifold after shutdown is troubling.

This is a Quicksilver remanufactured carburetor, BTW.

 

[zbnutcase]

Re: 470 2b carb flooding/starvation problems

I would lower the float level just a bit.

 

[natemoore]

Re: 470 2b carb flooding/starvation problems

I would lower the float level just a bit.

Nuther werds, make it so it sits lower in the fuel bowl when in the fully up and seated position (hence more bouyant force equal to the additional gas displaced)?

 

[cr2k]

Re: 470 2b carb flooding/starvation problems

There are very tiny holes on top of the main jet that sit in the venturi. If they get plugged gas will siphon from the float bowl regardless of float height. This is what the holes are there to prevent.

 

[guyaverage]

Re: 470 2b carb flooding/starvation problems

There are two different float needle options for this carb, one is spring loaded, the other isnt. Sounds like you have the one that isnt. If you change it to the spring-loaded version any dripping at idle or after shutdown will stop.

All you have to do is remove the needle, put the spring underneath, then reset the level and drop measurements if necessary. Any decent rebuild kit will have the spring in it.

 

[natemoore]

Re: 470 2b carb flooding/starvation problems

There are two different float needle options for this carb, one is spring loaded, the other isnt. Sounds like you have the one that isnt. If you change it to the spring-loaded version any dripping at idle or after shutdown will stop.

All you have to do is remove the needle, put the spring underneath, then reset the level and drop measurements if necessary. Any decent rebuild kit will have the spring in it.

Yes, I had both types when I rebuilt it last year. I reinstalled what was there originally--solid type. I'll try the spring loaded one and see what happens.