Twice now gas has poured out the over flow of my new NH carboutor. I readjusted the float level but it did not help. It will hold as long as I dont run the car, As soon as I go for a ride and stop it just pours out. At first I thought it might had been some dirt in the seat but it looks clean. Iv ordered a new needle and seat, gasket kit and a new inline filter for it. Its a new NH from Snyders.
Has the threaded gas inlet in the carb cracked ?
This happens frequently- here's what ya do: open the shut-off lever on the sediment bulb for 5 seconds, and then close it, then slowly crack it to slow down the fuel. The speed of the gas flowing down the pipe holds the needle open and you flood all over. Happens frequently to me as well.
Take it apart and make sure the carb float shutoff assembly is not a ball shaped device. If it is, it needs to be replaced with the original style or Viton tipped needle / seat.
I think the key word here is ,it is a "NEW" carb. Many problems with them. Likely just a faulty gasket on the needle seat. You can try tightening it up ,or replacing it. The new needles Larry Smith makes are good,and the right size.
I worked on a 'New' NH for a guy. It had sat up and needed a good cleaning. I don't know where it came from, but I was not impressed with it. The casting was poor quality and most of the parts that are normally brass, were zinc plated steel. Hope that is not a sign of what repair parts are going to start looking like. BTW, the float stuck on this one too, even after a good cleaning. Not sure why. Rapping on the side with a screwdriver handle finally made it quit.
Is the float rubbing on the body of the bowl causing it to stick?
Didnt seem to but then I didnt look at that very close. I will check that.
Switch out the float with an another, it may have a leak or poor buoyancy compared to an original(too much solder on the inside of the repo float). If it has poor buoyancy, setting it at the factory float setting will not work. You will have to find the correct float setting by trial and error or replace with a known good one.
As far as Buoyancy, a float either works, or it don't unless it is hanging up.
The only place the gas could over flow from is the seat, it is either bad, or hangs up from the float, or dirt.
My first guess would be that the float finger is not letting the needle seat at a 90 degree to the seat, or it would shut off.
Also if the air vent gets plugged, or some what, that also could give a like trouble.
My answer to the "new" carbs after having looked a couple of them over is WHY?? There is no shortage of NH's around nor people who do a good job rebuilding them. The bowls are readily available for a few dollars. If it were me I would take the new one off and send it back while I could still get my money back.
FWIW, buoyancy is the weight of the amount of liquid displaced minus the weight of the float. Many of the new floats are so heavy with solder and made of such heavy brass that they will barely float, let alone shut off the gas. Even if they are paper thin brass -- as most of the ones made in India that are sold by the vendors are -- they have solder inside the seam and don't have enough buoyancy to shut off the flow of fuel.
How about the gas tank? Does it have a sealer? Is the gas coming out of the bowl the same color as it was going in or darker?
Could be if its an older sealing job, ethanol could be softening the lining and you are gumming up the works.