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06-26-2020, 06:03 PM | #1 |
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Join Date: May 2010
Location: Longbranch, Washington
Posts: 513
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Zenith Carb. Issue
Which passage or jet might be plugged that only lets the engine run on near full choke ? Appreciate some guidance.
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06-26-2020, 06:36 PM | #2 |
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Location: brentwood, ca
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Re: Zenith Carb. Issue
Does gav have any affect?
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06-26-2020, 08:07 PM | #3 |
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Location: St Charles , Missouri
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Re: Zenith Carb. Issue
Look for a plugged cap and/or main jet.
Today’s fuels will gel fairly quickly if not run now and then. They are the two jets that are in the Venturi opening when you separate the halves Larry shepard |
06-26-2020, 08:56 PM | #4 |
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Re: Zenith Carb. Issue
Thanks fellas' - it sat with pump gas for some time. I disassembled it completely & soaked it in carb. cleaner - looked clean but no go ! I can check the GAV but I set it at 1 & 1/2 open to start- starts up right away but needs near full choke to keep her running.
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06-26-2020, 10:16 PM | #5 |
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Location: Lincoln, Nebraska
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Re: Zenith Carb. Issue
You don't mention if you used compressed air to blow the passages and jets out. If not I would suggest soaking again and blowing them out.
Possibly an intake manifold leak too. Check the tightness of the manifolds.
__________________
Dave / Lincoln Nebraska |
06-27-2020, 07:55 AM | #6 |
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Re: Zenith Carb. Issue
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06-27-2020, 09:26 AM | #7 |
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Join Date: Aug 2018
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Re: Zenith Carb. Issue
Possible worn Throttle Plate Shaft/Bushing? Check the shaft to insure it fits snugly in its bushing. Have heard this is also a source of a whistling noise.
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06-27-2020, 10:03 AM | #8 |
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Location: new britain,ct 06052
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Re: Zenith Carb. Issue
Vac leak either at the manifolds or where carb attaches. JMO
Paul in CT |
06-27-2020, 10:26 AM | #9 |
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Location: Longbranch, Washington
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Re: Zenith Carb. Issue
This was a new repro Zenith - I'll double clean & use the above suggestions - thanks !
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06-27-2020, 10:39 AM | #10 |
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Re: Zenith Carb. Issue
Since it was new, before messing with it much, call the vendor. They may have suggestions, and if it turns out to be the carb, a good vendor would want to be involved in case they want to exchange it. Once you have messed with it much, they may not want to exchange it.
Do you have access to another carb known good you could try? |
06-27-2020, 01:23 PM | #11 |
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Re: Zenith Carb. Issue
Already replaced with the Zenith the car came with after I replaced the throttle shaft on it - it runs fine. The "new" one was in a box that the fella got with the car - the car had been sitting a while & who knows when the replacement carb. was purchased !
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06-27-2020, 01:39 PM | #12 |
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Re: Zenith Carb. Issue
another option in case a good cleaning does not work. Try swapping in a flow tested jet kit, Renner's Corner is frequently mentioned om the FB as having good flow tested jets. Is not expensive.
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06-28-2020, 01:12 AM | #13 |
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Re: Zenith Carb. Issue
Correcting my post to say Dave Renner is still supplying flowxtested jets, just not rebuilding carbs any longer. It’s amazing by flow testing you can realize not even all jets point the stream of flow straight . Highly recommend flow tested jets if you can.
Special thanks to Dave Slater for updating me. Larry Last edited by larrys40; 06-28-2020 at 08:16 AM. |
06-28-2020, 03:50 AM | #14 |
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Re: Zenith Carb. Issue
Larry I think you have that slightly wrong. Dave Renner STILL sells flow tested jets for the A&B carbs. He just does not REBUILD carbs anymore. Dave
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06-28-2020, 08:10 AM | #15 | |
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Re: Zenith Carb. Issue
Quote:
Thanks for the update. Larry |
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