Bill Stephens Posted March 30, 2021 Report Share Posted March 30, 2021 Carb is Stromberg BXVD-3. I have rebuilt it several times over the last 15 years. Now engine as been rebuilt and sat for 4 years. Engine runs fairly smooth at higher rpms. Timing is set and advances OK. Unsure what I did last to the rebuild carb (4 years ago). Fuel bowl level is correct (5/8"). The idle circuit seem to not be working. Idle mixture needle adjustment as no effect. Screwed all the way in or several turns out. Also squirted carb cleaner thru idle mixture screw hole to no effect. Accelerator pump working. Maybe left out parts? Gasket installed backwards? All ideas appreciated. Also electric choke solenoid activates only when starter operates and returns to open when starter deactivates. Is that correct? All ideas/comments appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
allbizz49 Posted March 31, 2021 Report Share Posted March 31, 2021 Make sure the throttle shaft isn't sloppy. I chased the same problem with a holley 1904. Turned out the shaft was fairly sloppy where it went through the base and was sucking air through it. Quote Link to comment Share on other sites More sharing options...
Doug&Deb Posted March 31, 2021 Report Share Posted March 31, 2021 The choke does work when the starter engages but it shouldn’t fully open immediately. There is a bi-metallic spring that allows it to fully open as the engine warms up. If it’s been a while since you rebuilt the carb it wouldn’t be a bad idea to rebuild it again. The new kits are ethanol resistant. A new fuel pump with ethanol resistant diaphragm will eliminate future problems also. 1 Quote Link to comment Share on other sites More sharing options...
Sniper Posted April 1, 2021 Report Share Posted April 1, 2021 It's getting fuel at idle somehow, otherwise it wouldn't idle. I've seen where the idle speed adjustment was far enough out that the carb was running off the transition circuits and not the idle circuit, might not hurt to check that. Quote Link to comment Share on other sites More sharing options...
greg g Posted April 1, 2021 Report Share Posted April 1, 2021 an engine that doesn't respond to adjustments of the idle air screw is ikely to have a vacuum leak somewhere between the throttle butterfly and the intake ports. Do you have a vacuum gauge. Reading at idle should be 19 to 21 inches steady needlle at 450 to 500 rpm. Quote Link to comment Share on other sites More sharing options...
James_Douglas Posted April 1, 2021 Report Share Posted April 1, 2021 If the engine has sat for the last 4 years, and I am assuming the fuel was not drained out and or a pickling agent added, the water tied up in the alcohol in the gas probably separated and may have caused some corrosion in the carb. Pull the carb and tear it down and check it. Read my old posts on the BB carb and alcohol water separation and the step up piston sticking. Get a good car manual and just go through it and make sure it is in good shape. While the carb is out of the way, tighten all the intake nuts and exhaust nuts. Then try it again. James Quote Link to comment Share on other sites More sharing options...
Bill Stephens Posted April 2, 2021 Author Report Share Posted April 2, 2021 Throttle shaft is well worn with lots of play. Please suggest replacement source or method of repair. Thanks for all help and comments Quote Link to comment Share on other sites More sharing options...
chrysler1941 Posted April 2, 2021 Report Share Posted April 2, 2021 Just want to add regarding the electric choke, or Sisson Choke as it's called, often has burnt insulating gasket. This will affect the opening timing. Quote Link to comment Share on other sites More sharing options...
chrysler1941 Posted April 2, 2021 Report Share Posted April 2, 2021 30 minutes ago, Bill Stephens said: Throttle shaft is well worn with lots of play. Please suggest replacement source or method of repair. Thanks for all help and comments There is a seller on ebay who sells a kit for carbs. It consists of brass bushings and correct reamer. Quote Link to comment Share on other sites More sharing options...
Young Ed Posted April 2, 2021 Report Share Posted April 2, 2021 38 minutes ago, chrysler1941 said: There is a seller on ebay who sells a kit for carbs. It consists of brass bushings and correct reamer. We had a good thread here for carter carbs. I bought a reamer and some oilite bushings from mcmaster and did one of my b and b carter's pretty easily. The trickiest part is taking apart and reassembling the throttle plate Quote Link to comment Share on other sites More sharing options...
Sniper Posted April 3, 2021 Report Share Posted April 3, 2021 thread on bushing carb base 1 Quote Link to comment Share on other sites More sharing options...
Bill Stephens Posted April 6, 2021 Author Report Share Posted April 6, 2021 Thanks for all responses. The brass throttle shaft is 1/4". Surprise, no supplier seems to make a bushing kit for this size or a replacement shaft. The carb base is cast iron which is why the brass shaft is worn and not the base. I am considering soldering bushings on the throttle shaft at the wear points and drilling out the carb based to accept the new diameter. Any thoughts? Also the electric choke almost full closes when starter is activated but releases immediately when starter is deactivated. The bi-metallic spring I believe is meant to hold it close and gradually allow it to open as the engine warms. Does the present action mean the spring has failed or out of adjustment? Can it be adjusted? Thanks. Quote Link to comment Share on other sites More sharing options...
chrysler1941 Posted April 6, 2021 Report Share Posted April 6, 2021 EnjoySisson Choke Manual.pdf Quote Link to comment Share on other sites More sharing options...
Sniper Posted April 6, 2021 Report Share Posted April 6, 2021 1/4" carb bushings https://www.carburetor-parts.com/Brass-Throttle-Bushing-22-4-1_p_441.html No mention of a reamer, might talk to them about that. Quote Link to comment Share on other sites More sharing options...
Bill Stephens Posted April 10, 2021 Author Report Share Posted April 10, 2021 I purchased 1/4" bronze bushings from Ace hardware (about $2 ea.) from their speciality hardware drawers. Wanted to try the K&S Precision Metal thin wall brass tubing sold for hobbyist they usually carry but were out of the sizes I needed. Drilled the throttle body on my drill press using a drill press vise, alot of eye balling and sweating bullets . Pressed and glued(super glue) the bushings in using a 1/4" rod for alignment. Extended one bushing out the throttle cam side and drilled out the cam to fit. The cam had an oval shaped hole and the old throttle shaft had a deep wear grove resulting in lots of slop. All actions seems to work smoothly without binding and is tight. Will report the final results when back installed on the car. Thanks for all comments. 1 Quote Link to comment Share on other sites More sharing options...
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