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04-25-2014, 05:02 PM | #1 |
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Zenith gav valve question
The float is set at 5/8". What would cause the motor to stop runing when the GAV valve is closed while the car is idling?
Thanks again Charley |
04-25-2014, 05:08 PM | #2 |
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Re: Zenith gav valve question
Is this relating to Zenith Model B on a 4 cylinder car ?
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04-25-2014, 05:10 PM | #3 |
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Re: Zenith gav valve question
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04-25-2014, 05:12 PM | #4 |
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Re: Zenith gav valve question
Nearly midnight here in the UK.....I'll try to come up with something tomorrow
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04-25-2014, 05:43 PM | #5 |
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Re: Zenith gav valve question
GAV should be about 1/2 turn open to star and idel, going down the road with an wamed up engine you may be able to shut it down. How far "open" do you have it to make it run good?
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04-25-2014, 06:22 PM | #6 |
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Re: Zenith gav valve question
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04-25-2014, 06:26 PM | #7 |
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Re: Zenith gav valve question
Sounds like a small bit of rust or other gunk finding its way into one of the main jets. Try blowing them all out backwards with carb spray and compressed air.
You should expect GAV to be open 1/4 turn on a warmed up engine and open about 1/2 turn when cold (even more when starting in really cold weather). Set the idle speed and mixture on the carb with the engine fully warmed up and GAV open 1/4 turn.
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04-25-2014, 06:27 PM | #8 |
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Re: Zenith gav valve question
Could be the foot throttle is hanging up and not coming all the way back. Might need lubrication or a new spring or is bent.
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04-25-2014, 08:45 PM | #9 |
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Re: Zenith gav valve question
I agree sounds like a small piece of dirt. Or it could be a air leak between carb and manifold.
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Jon "If you choose to not decide, you still have made a choice!" RUSH Don't tell me what you know..... Tell me what you have done. |
04-26-2014, 03:34 AM | #10 |
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Re: Zenith gav valve question
My ModeL B Zenith suffered similar problems and I finally sent it to Dave Renner for a rebuild.
Dave is The Guru for these carburettors. When the carburettor re-appeared in the UK I then had a different car which would drive, idle and never stall with the GAV fully closed. Recently the carb has picked up a bit of dirt somewhere and now only drives happily with the GAV open about 3/4 turn on a warm engine. It will idle with the GAV closed when warm but any attempt to accelerate is greeted by a struggle and an occasional backfire. Dave Renner has suggested cleaning out the compensator and main jets followed by the Cap jet. I've jet to pull the carb apart and give it a go. |
04-26-2014, 04:28 AM | #11 |
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Re: Zenith gav valve question
I agree. This would be the easiest thing to check, and therefore the first thing to check.
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