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Old 01-18-2019, 10:49 AM   #1
Rusty Karz
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Default GAV Question

Should I be able to completely cut off the fuel to the engine with the GAV turned all the way clockwise? It seems to run and start in that position ok. Is that normal or do I have a seating problem?
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Old 01-18-2019, 10:58 AM   #2
cpf240
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Default Re: GAV Question

No.

It adjusts the mixture, does not shutoff fuel.
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Old 01-18-2019, 11:09 AM   #3
Rusty Karz
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Default Re: GAV Question

Thanks. That is what I was unsure of.
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Old 01-18-2019, 12:42 PM   #4
Purdy Swoft
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Default Re: GAV Question

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Originally Posted by cpf240 View Post
No.

It adjusts the mixture, does not shutoff fuel.


If you are running a model B carburetor you should run the GAV closed all the way to the right after warm up . If you are running the Zenith one or two the GAV needs to be opened one quarter turn to the left after warm up. The pot metal replacement carbs sometimes need to run a bit richer depending on the condition of the carburetor . If the engine is running too rich it may may lope at idle and you may see a little rich black smoke out the exhaust . If running too lean the engine may backfire . Running too lean will probably cause more problems than running too rich .
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Old 01-18-2019, 01:39 PM   #5
CHuDWah
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Default Re: GAV Question

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Originally Posted by Rusty Karz View Post
Should I be able to completely cut off the fuel to the engine with the GAV turned all the way clockwise? It seems to run and start in that position ok. Is that normal or do I have a seating problem?

Your question is answered in the responses above, so this may be stating the obvious and/or what you already know, but...

Turning the GAV adjusts mixture - pulling it up is choke. SOP is to open it full turn and choke to start cold engine, then adjust to quarter turn when warmed up. But every engine is different so you'll have to find the exact adjustments where yours is happy. There is a valve to shut off gas under the tank.
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Old 01-18-2019, 03:24 PM   #6
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Default Re: GAV Question

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Quote:
Originally Posted by Purdy Swoft View Post
If you are running a model B carburetor you should run the GAV closed all the way to the right after warm up . If you are running the Zenith one or two the GAV needs to be opened one quarter turn to the left after warm up. The pot metal replacement carbs sometimes need to run a bit richer depending on the condition of the carburetor . If the engine is running too rich it may may lope at idle and you may see a little rich black smoke out the exhaust . If running too lean the engine may backfire . Running too lean will probably cause more problems than running too rich .
Is this the same with a Simmons carburetor Purdy
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Old 01-18-2019, 03:50 PM   #7
Purdy Swoft
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Default Re: GAV Question

Joop ,

I run my cast iron Simmons carbs about the same as I run my Zenith one and two carburetors . I mostly set the GAV at one ouarter turn after warm up .
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Old 01-18-2019, 04:58 PM   #8
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Default Re: GAV Question

Thanks
That’s what I do
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