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Old 08-05-2017, 07:30 AM   #1
PRG999
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Default Marvel carbeurator question

I have a marvel carb that I have cleaned and rebuilt. When running I have a small amount of gas weeping from the float bowl vent. How do I stop this?

Also would this be the reason I am getting 10 mpg with it on a properly timed rebuilt engine? I know I have the GAV set properly as when I have the GAV fully closed the motor bucks, at 1/4 open it runs strong.

Thanks
Paul
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Old 08-05-2017, 09:59 AM   #2
duke36
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Default Re: Marvel carbeurator question

Seems like float level is too high or float valve is sticking. What type of float valve? The only one found not to leak for me was the viton tip --with ethanol laden gas. The round ball style didn't seal well. Are all fibre washers in place ? Also check that GAV has leather or (vendor's replacement) rubber washer down at tip. This can make the GAV rod hard to turn unless pulled up a bit.
GAV 1/4 or a tad less open is what I run at normal temps. This depend on needle tip or seat condition. Pull a spark plug and look at color of electrode.
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Old 08-05-2017, 10:44 AM   #3
1930artdeco
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Default Re: Marvel carbeurator question

10 seems a bit low, you should be in the 15 range. It has a bigger throat than the zenith so you will use more gas.
Mike
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Old 08-06-2017, 04:07 AM   #4
PRG999
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Default Re: Marvel carbeurator question

Thank you for the responses.
I believe all the fiber washers are in place, I will recheck that. The GAV has a new rubber washer.

The float valve is the original one.
I tried to install the round ball one type float valve from renners but it would not seat properly- the unit seemed to wide to properly screw in.

Where does one get a viton tip replacement?

Thanks
paul
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Old 08-06-2017, 07:08 AM   #5
jhowes
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Default Re: Marvel carbeurator question

I get closer to 20 mpg with my Marvel. The original tip lapped in with toothpaste has worked for me.
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Old 08-06-2017, 06:57 PM   #6
Herb Concord Ca
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Default Re: Marvel carbeurator question

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Steiner Tractor sells a viton tipped float valve that may fit your carb.
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Old 08-06-2017, 07:05 PM   #7
1930artdeco
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Default Re: Marvel carbeurator question

Paul,

It sounds like you have the smaller sized float valve. If Thetis the case the you will have to get the one from Steiner's and modify slightly. You just have to shorten it on a grinding wheel. That is what I did with mine.

Mike
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