help with a carberater

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Feb 27, 2015 | 08:43 PM

tpvegas

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help with a carberater

I have a question on fuel mileage I have an 81 f 250 with a 351 M Holley 600 carburetor and I'm getting four miles to the gallon any help would be appreciated

Feb 27, 2015 | 08:46 PM

ctubutis

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From: Denver Metro Area, CO

What transmission? Where in the country are you located?

Feb 27, 2015 | 08:47 PM

tpvegas

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T18 transmission las vegas

Feb 27, 2015 | 09:44 PM

Gary Lewis

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From: Northeast, OK

You probably have a blown power valve. That will kill gas mileage on a Holley. As will a stuck-on choke - on any carb.

But, we really need to know a whole lot more about your truck. Are you running huge tires? How fast do you drive when getting 4 MPG? Have you changed anything just before the MPG went south? Or, has the MPG ever been better?

Feb 28, 2015 | 01:45 AM

Trackerrrr

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From: Lake Elsinore

Quote:

Originally Posted by tpvegas

I have a question on fuel mileage I have an 81 f 250 with a 351 M Holley 600 carburetor and I'm getting four miles to the gallon any help would be appreciated

I live in Henderson and get 8 mpg with my dually. Is your speedo accurate? If it's running slow your mpg calculations will be off.

Feb 28, 2015 | 02:00 PM

tpvegas

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I have stock 16 on my truck what would happen if I get a plug for the power valve I drive 65 on the free way

Feb 28, 2015 | 03:01 PM

Gary Lewis

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From: Northeast, OK

If you plug the PV hole you won't have any enrichment. If the carb is jetted about right when you want to accelerate more than gently the engine won't want to do anything. And it'll either refuse to do more or bog until the secondaries open. IOW, don't do it. Fix the problem, don't create another one.

So, getting 4 MPG @ 65 MPH with stock tires. That means you have a pretty significant problem - like the choke not coming off or a blown PV. Check the choke by getting the engine warm and then pulling the air cleaner. The choke butterfly should be standing straight up and down.