VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Carburetor Issues 1931 Chev RJH 08 150S

I recently had my carburetor rebuilt. The engine starts up and runs just fine with choke half way out. Even when engine is warm it stalls out when choke is pushed in. I have tried it with throttle cable pulled 1/4 inch out to increase rpms but as soon as i push choke in from 1/2 pulled out position engine stalls. I have adjusted spark plug gap to .040, dwell at 36, and adjusted valves to proper tolerance. I have checked for vacuum leaks around intake manifold and carburetor attachment to manifold, cannot find any leaks.
Reading various articles on low idle jet, i was wondering if I am having issues with the low idle jet. I took off carb and submersed it in carb cleaner but I am experiencing same
issue where the choke neeeds to be pulled 1/2 way out in order for engine to idle. Look forward to your suggestions

when you installed it did you (all from repair manual)

set the cables and such correctly, so the choke is closed fully when it should be, and open when should be when pulling pushing the knob ??
adjust the idle and such using the adjustment screw
adjust the float to the proper 3/4"

make sure all items move properly and freely

Idling Adjustment
To adjust, proceed as follows:
To adjust the idling mixture, open the idle adjusting screw from % to 1M turns, or until the motor hits evenly without loading or missing. Turning this screw to the right produces a richer mixture.

The correct level is 3/4" from the top of the float to the machined surface of the casting when the needle is closed. This measurement should be taken on the side of the float opposite the gasoline intake needle, using a steel scale and measuring from the machined surface of the casting.

All carburetor rebuilders don't have the knowledge or tools to accomplish a correct rebuild. When you get tired of messing with it send it to one of the experienced 1931 carburetor rebuilders that frequent this site.

that would be a good question, WHO rebuilt it ?!?

I know of a FEW Skilled Quality Rebuilders around the VCCA :p

I had it rebuilt from a company in St. Louis, MO. I appreciate everyone’s responses. I went thru the carb again over weekend and checked all settings. Reinstalled with new gasket, started right up but experienced the same condition as before. Will run at idle only when choke is pulled half way out. I checked by spraying carb cleaner into low idle jet that it is open, and blew air thru it also. If you could please share what shops you have found that can give me a functioning carb when they have gone thru it. Thanks again for your help

Both "Chipper" and "Junkyard Dog" on this site have rebuilt hundreds of these RJH-08 carburetors. Both have the parts and the expertise to do it right and either one will do it at a reasonable price. You should send them a PM with your phone number and ask them to get in touch.

All the Best, Chip

Money well spent as far as I am concerned.

Worth every , I mean Penny

Superb Guys - Superb Workmanship

Removing the low speed jet can cause idle issues.

The "free" end (top) of the idle jet is forced into a tapered passage when the lower plug is tightened. Once removed, the idle jet may be re-used, BUT ONLY IF THE OUTER DIAMETER OF THE FREE END IS EXPANDED FIRST. Otherwise the idle jet will not seal at the top and the engine will have a lean idle.

Jon.

Jon, What do you use to expand the free end?

Thanks

Dave

I use a tapered punch but anything that is round and fits into the ID when rotated around will flare the tube out a bit. Not too much as it needs to fit into the 1/8" hole before bottoming out at the taper. A very thin coating of solder on the end also works. Be careful because too much resistance at the end of the tube when installing can break the low speed jet at the narrowed part. Then you have a real problem unless you have a special tool to extract the broken off end.

Looking at the open end of the low speed idle tube is perfectly round and smooth, shows no sign of flaring or solder. Knowing this am I better off sending it to the clubs approved rebuilders to get it totally checked out or try to find a machinist locally that can do the flare. Sounds like it is a tricky yet essential piece to get the carb idling properly

Dave - I CAREFULLY use an icepick. The metering orifice is NOT at the top, so not a problem. Just insert the icepick tip into the free end and "roll" it around. A few thousanths expansion is all that is necessary. Learned this trick from the Carter school instructor when Carter was still offering tech schools.

This same issue applies to ALL of the Carter W-1 carbs used on Chevrolet.

Jon.

Independence - if this was not done by the rebuilder, then the rest of the work is suspect as well.

I would suggest you send it to one of the folks on here (NOT me, no longer rebuilding, too busy with the manufacture of parts!).

The Carter brass bowl carb is not a really difficult carb, if one knows what one is doing, and has access to both special tools and parts. Otherwise, best left to someone who does.

Jon.

Chipper and Jon, thanks for the info

If Chipper and Junkyarddog could please contact me and see if one of them would be able to rebuild my RJH08 150 carburetor
Thank You
Contact info Everett 651-257-1420

Either of us can do the rebuild if the parts are in good shape, particularly the cast iron body. I will send you a PM. Look for the flashing envelope in the upper right.