VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 float works........

I got the new float and needle valve from Don Rossi. I put it in and away I went. All looked and sounded good.

Then........ after it warmed up I noticed a hesitation and when I came to a stop it wouldn't idle. I guess I need to start looking for that vacuum leak you guys were telling me about.
If I'm thinking correctly in the manifold that the carb bolts on to and go to the head right? :confused: :rolleyes:

I will start looking tomorrow.

I also wonder if I need to put a gasket sealer on the reinstalled carb. I have had it off a few times (nw)and I have not put any sealer on the fit. I guess that could be suspect too :rolleyes:

Shocks

Put on a new flange gasket instead of using gasket sealer.

Is it possible that some valves are set too tight and are not closing completely when the engine warms up?

George

Well my problems continue. Everything was going well until I took it out and ran the old guy for a while.
Then it just wouldn't idle. I have to pull the throttle out to keep it running. Then it seems ruff.
I did take your advise and made a new gasket after I sprayed the carb neck and it speed the engine up. But after the new gasket it still does the same. I sparyed the carb neck again and it "still sped up??? I took the carb off and inspected the chock plate assembly. It has some play from side to side which tells me I could be pulling air in there. I think this could be a contributor but can't be all the problem.
I took off the valve cover lid and with is running I checked the gaps with a .007 feeler gage. Just to see if I had a tight valve. I slipped through OK on all valves. I guess my problem still lies in the carb.
ACTION PLAN.......I'm thinking about changing the neddle valve I got off Don R. and putting in my original one. When I put it in I tested it in the shop by lifting up the float sometimes it didn't drop? Without pressure behind it this could be normal....right? The other thing which is different is I have to give it more throttle and chock to start as if it doesn't have the necessaryt gas?
The last thing I am thinking about doing is taking the choke assembly apart. Since its brass I thought about soldering the shaft with a light coat of solder where is sits in the carb casting. This could act as a babitt to seal the possible air leakage there. This action seems a little over reactive.
Shocks

Just a thought, don't know the full thread but.....Could this be an HT problem? Leads or something breaking down when hot?
Sometimes it's all to easy to get stuck down the wrong route.
Try a mist of engine start where you think the leak is, ONLY a mist mind, if the engine picks up you've found your leak.

Either you still have a vacuum leak or the low speed idle circuit in your carburetor has a problem. I'm going with the low speed idle circuit since you must pull the choke out to make the car idle.

Also, the needle valve should go up and down easily when you move the float up and down.

It is common for a used (worn) carburetor to leak some air around shafts. Spraying a flammable around the shaft and having the engine speed up is also common. The key is does it significantly change with running (heat).

The choke section of the carb could be part of the problem but not likely the major contributor. Air leakage in the carb will not be as affected by temperature as other components. Air leakage at the carb therefore will be relatively consistant. Idle changes during operation can be a result of carburetor part movement that changes the amount of leakage. I hope that the above is not confusing.

Replacing the shaft or bushing the carb body or both is the best solution. Soldering is not likely to be a good solution.

A dry needle is much more prone to stick than a wet one.

Did you verify that the amount of gas in the carb was consistant when it was running well and not idling?

The problem could be electrical as well as carb. Is the spark intensity the same when running well and when poorly?