OK, I'm up against the clock...
We have Cindy's '27 Coupe registered for a show tomorrow morning. I purchased a brand new (not rebuilt) Holley NH and have had a rough time getting everything to work. After three weeks of issues, I finally have the manifold, pull rod, fuel line, choke wires, etc. all worked out.
Now for the problem: When I turn on the gas, fuel pours out of the bottom of the carb... not the top vent, the bottom. If I remove the bowl, I can hold up the float & the needle seats and shuts off the fuel... with the bowl on, it never fills... just shoots gas out of the bottom. Everything seems tight. Gasket is on the outside of the bowl as it was supplied to me. Float level is to spec.
Any ideas what I'm doing wrong?
Typically the new NH carbs come with a needle and seat that doesn't work. This seat is a steel cylindrical needle with a coil spring that centers the needle in the brass seat housing. If it has this type of seat remove it and replace it with a viton or gross jet shut off valve.
Float hitting or rubbing on anything when bowl is put on ?
Bottom gasket gone?
Needle & seat were changed out for new neoprene or viton (not sure which)version. I should have stated that.
Gasket is there.
I can feel the float flopping up & down when assembled. No apparent binding. I'm just not sure how the gas is getting past that bottom fitting?
Cracked bowl drain fitting or bowl ???
I think the float is no good and you have to solder it up or find a replacement fast, too bad your not near me because I would've lent you one of my extra nh's
Be sure the bottom gasket is on the outside under the nut.
I found the problem. As always, I have Cindy look at the issue & she gives me ideas of where to look
The bottom drain valve does not seal. I can blow air through it & air comes out the side hole on the OUTSIDE of the fitting. I tried a water test as well with the nut pushed against the bowl off the carb... water runs right through it. Too bad I'm just finding this out at almost 8:00pm. We'll table this project and take the '15 Touring again this time.
Thank you for the ideas
Can you barely crack the gas shut off open and attempt to see if the leaks is from the nut area or the drain area?
Bill, was there an NH on there before? use the fitting from the old carb or get one from your Dad!
It comes out of the drain area... That's what I observed on the car but wanted to make sure. The compressed air test confirms it. The part is just machined wrong. I'm out of time tonight. I haven't been able to test drive with the new carb & don't want to make a trial run without time to check things for safety. Going to start getting the '15 ready.
Thanks again everyone
Jeff: It had a Vaporizer... I think it's different. Dad doesn't have stock stuff... just hot rod T parts.
Are you going to Belmont Shore tomorrow? That's what I'm preparing for.
Bill, I didn't plan to go, I had a project to work on, but I was just informed that we are going to breakfast in the shore tomorrow, so I will be looking but not showing. So much for my project! Actually it's more like brunch for this bunch since the place doesn't even open until 10:00. Breakfast should be in the morning!!!