Float problems on 6 pack

[70sixpkrt]

2 weeks a go I put a new gas tank and sending unit. Last week my rear carb was coughing up gas so I pulled the needle and seat and cleaned it. Today it was surging on the freeway. I got home and checked the sight plug. Gas was pouring out of the sight hole. I adjusted the float down a little and no gas was coming out of the hole. Not even a dribble. This was with car off and shaking the car a little with my hip. So I adjusted the float a tad. Now gas is pouring out of the sight hole again. I did put the float in a cup of water and noticed no bubbles. Does this sound like a bad float? I noticed the the idle was about 1400 when the float was high. Can the idle be high with a high float? I did order a new float just in case.

[charger Downunder]

I have always adjusted mine with the car running, put in a new needle and seet

[BSB67]

I have always adjusted mine with the car running, put in a new needle and seet

What he said.

It is likely the needle and seat.  Pull it out and clean it with cleamer and compressed air.  If the problem continues, replace the needle and seat. It is a two minute job as you can pull the assembly out without taking off the bowl.  I usually keep new needle and seats in my carb spare parts box.

Fix this first, then move on to the high idle, if that is still a problem.  But does make me wonder if you have a vacuum leak.  What is the idle quality normally? (in. of vacuum at what rpm), and what is your cam overlap?

[70sixpkrt]

New needle/seat. No vacuum leaks.

[BSB67]

I would probably still try a another needle and seat, or switch one from one of the other carbs.

Obviously you can check if your float is sinking too, so I assume you have done that, and that is not it.  Not sure how it can get hung up, but guess that it is possible.

There is only one way that a change in the induction system will make a engine run at a higher rpm if the throttle stop has not changed.

[70sixpkrt]

Thanks for the suggestions. What I did was took apart the rear carb and cleaned it. Replaced the needle/seat and float. Changed gaskets. Set the float inverted. Got it running. Took it for a small ride and came home. I left it running and checked the sight hole. With it running it just trickled out. Right now it's running good. I know in a couple of weeks, I'm going to take off the center carb and do the same thing. I think it was the float hanging up. Crossing my fingers.

[BSB67]

FWIW, I keep needles/seats just for this reason.  And I have had to back to the same one more than once to get it to work.  Every few years on my six pack it seems one of the carbs have this problem.  Glad it working.