Is Your MUTT Bucking?

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64 M151
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Is Your MUTT Bucking?

Unread post by 64 M151 » August 29th, 2017, 10:12 pm

Is your mutt still bucking after a CARB rebuild. Mine was and after a rebuild or two it ran fine for about 5 miles then started bucking again. At times it acts like it ran out of fuel and times it acted like the power went dead. I replaced DIST internals, fuel pump, circuit breakers and rebuild CARB with NOS kits. Still ended up with the same results. Bucking and Bucking and got so sick and tired to the point of giving up but that's not me. I found a site that has fresh brand new Carbs and Carb Kits. Well I ordered a new CARB KIT and rebuilt for the 3rd time. Still got the same result and said to my self I replaced everything so what did I not replace. So I said the float. So I checked my old one and it floated so what is the problem. Well I forgot that I left in a bucket of gas and the next morning it was not there. It sank to the bottom of the bucket. So I research the same site where I got the CARB Kit from for a float. I ordered one and installed it and haven't bucked since.
The float is preset.
FLOAT = PN: ZENITH / C85-127
https://norfar.com/collections/carburetor-floats

CARBURETOR = PN: Zenith 13660 Carburetor - Replaced by 13660B
https://norfar.com/products/zenith-13660-carburetor

CARBURETOR REBUILD KIT = PN: ZENITH / K2167
https://norfar.com/collections/carburetor-kits?page=2

Hope this fix your MUTT, Joe
" Apply The 6 P theroy" (Previous Planning Prevents Piss Poor Performance)"
" When something becomes FUBAR We Blame it on SNAFU Then Try to SWAG Our Way Out of it"
"Just my Wooden Nickels worth"

Dakota
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Re: Is Your MUTT Bucking?

Unread post by Dakota » September 6th, 2017, 2:47 am

I replaced the old engine with an new one (including carb) but it continues to buck :cry: . My engine was probably assigned for use as an generator (fan blowing forwards, no oil tap plug) . I have turned up the mixture screw, but it is only pulling the choke out that Cures the problem .

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rickf
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Re: Is Your MUTT Bucking?

Unread post by rickf » September 6th, 2017, 10:18 am

Your engine came off of a Hawk missile loader. Would have been bolted to a C4 Ford automatic transmission originally. Does it have a fuel pump on it? The missile loader would have originally had a hydraulic pump covering that area and a block off plate would be on the block. An electric pump was used. You don't want to drive down the road with that fan since it will cancel out any airflow trying to come in the front and you will overheat. Sounds like the carb needs a good cleaning and probably a float reset. They all used the same engine settings. Be sure all of the usual tune up settings are right. Valves and timing have to be right on the money.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Dakota
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Re: Is Your MUTT Bucking?

Unread post by Dakota » September 6th, 2017, 10:36 am

No fuel pump, had to use the old one , re used my old fan also :) . Timing checked and it is correct. Had to install a fuel return line to the fuel tank as the carb was flooded.

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rickf
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Re: Is Your MUTT Bucking?

Unread post by rickf » September 6th, 2017, 10:50 am

I know a guy that sold a bunch of these engines a few years ago, where did you get yours from? The return line will not cause nor will it relieve flooding. If the cab is flooding then there is a problem either in the carb or the fuel pressure is too high. The return line can be eliminated without any consequence, it is only there to prevent vapor lock.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Dakota
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Posts: 11
Joined: January 19th, 2011, 1:02 pm

Re: Is Your MUTT Bucking?

Unread post by Dakota » September 6th, 2017, 5:13 pm

My engine came from an army surplus auction here in Norway. I suppose it was left behind by US-armed forces. My Mutt is an A2 with mechanical fuel pump and from the TM's I notice the fuel return line. The engine has never been started before, but I suppose a good cleaning of the carb could not hurt.

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rickf
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Re: Is Your MUTT Bucking?

Unread post by rickf » September 6th, 2017, 7:47 pm

And check the valve clearance and the timing, All of those things need to be perfect for it to run right. I also would not hurt to pull the hand throttle out a bit to raise the idle to a high idle and then spray some carb leaner all around the intake manifold, be sure to get under the manifold also. Listen for any change in the way the engine runs. Be sure to have the air cleaner tube hooked up while doing this. If there is a change try top narrow down the spot that makes it change and you have found a vacuum leak in the intake gasket. Pretty common with these.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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