Slight WA-1 Carburetor issue

railknight
railknight Expert Adviser
edited September 2022 in HUDSON
I have a Twin-H, WA-1carburetor set up on my Super Wasp.  The car runs fine starting, idling, accelerating and at cruising speeds.  The only minor issue I have is that when coming to a stop with my foot off the gas pedal the engine runs just a tad fast.  This slightly fast idle is immediately brought down to a smooth slow idle with just a slight tap on the gas pedal.   When I accelerate again, it goes back to the faster idle speed each time.  

I checked out the linkage for any binding and even sprayed some carb cleaner on the carburetor linkages, but this hasn't improved things.  Before I start messing around with adjustments on the carburetors themselves, any idea where I may want to look?  Thanks for any advice here!
Dan

Comments

  • Glowplug
    Glowplug Expert Adviser
    edited September 2022
    Dan interesting that you are posting this problem.  A friend recently purchased a hornet which is equipped with Twin H.  After a through exam of the cars tune we determined the following to be the cause of a similar return to idle condition.  The carburetor base contains the primary accelerator linkage which is cross linked to the metering rod circuit.  The linkage on the front carburetor was moving on the cross shaft.   This in turn caused the meter rods to float and when this occurred the idle was unstable.  Replacing the base with one with tight linkage to cross shaft stopped the idle problem.  This car was also missing the return spring on the rear carburetor linkage as well as both return spring anchors.  Adding these missing parts contributed to assuring the cars engine idled properly.   
  • I've noted the same issue GlowPlug describes. It seems the throttle valves on these carbs are showing their age. It makes synching the carbs fun too. It's not a big deal if you can find a decent base to replace it, but those are getting less common. 
    I'm curious if anyone has experimented with alternative, new build carbs on their Twin H setups.
  • 50C8DAN
    50C8DAN Senior Contributor
    This is one reason I decided for the new aluminum intake to go with Weber carbs since they are still in production and parts are plentiful.  Weber does make the ICT and ICH single barrels as well, made in Spain.  Almost all other carbs are either rebuilt or Chinese knockoffs.  I know that there are a number of companies selling reproduction Holley 94s and Stromberg 97s and they seem to be OK?
  • railknight
    railknight Expert Adviser
    Well thanks for the suggestions and comments.  Still have the issue, though it's certainly something I can live with, just a bit of a frustration.  I'm thinking that the Twin-H return springs from the carburetor to the linkage over the engine appear a bit anemic and perhaps as stronger one or two might help.  
  • It may go without saying, but replace the springs in pairs.
  • railknight
    railknight Expert Adviser
    Yes, I'll try two new springs.  I have a box of springs somewhere, just can't remember where I placed them.  
  • railknight
    railknight Expert Adviser
    Today I went to Menard's (as in, "Save Big Money") and purchased two new springs with greater tension (though not excessively).  I attached them between the two carburetors and their respective linkage and took the Super Wasp for a test spin. 

    What a difference.  No higher than usual idle when coming to a stop.  In fact, the idle may now be a tad on the low side, though the amp light doesn't come on when idling even before the engine warmed up fully.  Thanks again to Glowplug, superwasp and 50C8DAN for your suggestions.   
  • Glowplug
    Glowplug Expert Adviser
    Railknight thanks for the update... enjoy your car!
  • JasonNC
    JasonNC Expert Adviser
    Railnight, I have had the same issue that you mentioned in your original post.  There isn't a Menard's that I am aware of near me in NC.  (Never heard of them).  Where can I get replacement springs other than Menard's?
  • I found mine at a local ranch and home store like Tractor Supply or Murdoch's that has a decent hardware section. They were surprisingly close to the originals in length and diameter. I had to shorten mine just a bit, but not very much.
  • railknight
    railknight Expert Adviser
    JasonNC:  Menard's is a large store in the Midwest pretty much like Home Depot or Lowe's.  superwasp's suggestions are good places to check for return springs.  Also, I just looked at the NAPA website under carburetor springs and got quite a few ones to consider.    
  • JasonNC
    JasonNC Expert Adviser
    Thanks guys.  Just to make sure I'm getting the right kind of springs, can one of you guys post a picture of your new springs on the throttle or the package they came in?  
  • I'll grab a picture for you when I get a chance. I'll see if I can find the original to compare. Mine were not packaged as they were in plastic bins in the bulk hardware section.
  • railknight
    railknight Expert Adviser
    The back of the two packages I purchased that the springs were individually sealed in from Menard's reads:  3/8 x 4 x 0.38 WG, Midwest Fastener, Kalamazoo, MI. These springs were a bit different in length and width, though pretty much the same wire size, versus what I originally had on my Super Wasp.  I chose to buy them as they had somewhat more strength than the old springs.