another carb question

1959 - 1978, M151, M151A1, M151A2, Technical questions and discussions, regarding anything related to the M151.
ldj1002
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another carb question

Post by ldj1002 » Thu Mar 24, 2022 10:58 am

On the Zenith carb is there a spring under the diaphragm, and which way does it go?
I got the float set, what a job trying to bend it and worrying about tearing that medal piece out of the float material.
The 3/8" minimum is probably 7/16. Don't see what that hurts so long as it doesn't drop down to cause the needle to to get cock
eyed. Didn't won't to mess with it any more and take a chance of damaging the float.
Leo


hambone
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Re: another carb question

Post by hambone » Thu Mar 24, 2022 1:42 pm

carburator1 (1).jpg

Rickf
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Re: another carb question

Post by Rickf » Thu Mar 24, 2022 2:59 pm

The spring goes between the cover and the diaphragm. And setting the float you should not be anywhere near the float material, The setting is done with the float out and the bend done on the arm close to the pivot pin. Your float drop setting will be fine. Did you get the float height setting at 9/32? That is from the gasket to the float.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

ldj1002
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Re: another carb question

Post by ldj1002 » Thu Mar 24, 2022 3:01 pm

I got the spring on the wrong side. Thanks

ldj1002
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Re: another carb question

Post by ldj1002 » Thu Mar 24, 2022 3:05 pm

I set float 3/32, I read that somewhere.
Leo

Rickf
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Re: another carb question

Post by Rickf » Thu Mar 24, 2022 5:50 pm

You read the one manual that had the wrong settings!!!! The correct setting is 9/32. 3/32 you will have serious flooding issues.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

ldj1002
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Re: another carb question

Post by ldj1002 » Thu Mar 24, 2022 7:14 pm

OH my, thank you. I'm glad I haven't put it on yet. I have worked on lot of carbs in past and most settings have the float about level with base when held upside down. The 3/32 had the float close to level so I thought this seems good. I use a drill bit of the right diameter to set float. I feel that is better than eyeballing a scale.

Tech3140
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Re: another carb question

Post by Tech3140 » Sun Mar 27, 2022 4:34 pm

9/32” that’s the settings???
Great advice. I have a new Zenith carb I got free from Surplus City a few months ago.
Now, my question is: what is the best way to check the float?

Rickf
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Re: another carb question

Post by Rickf » Sun Mar 27, 2022 4:53 pm

If you do not know how to check or set the float it is best to look it up in the -20 manual. It would be hard for me to explain it when you are not somewhat familiar with carburetors. And there are several things that could go wrong in taking it apart, especially losing the idle jet from the bowl as you take the bowl off.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Tech3140
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Re: another carb question

Post by Tech3140 » Sun Mar 27, 2022 7:25 pm

Ok, Maybe I got lucky. But way back in 1985 when I drove my M151A1 all the way from Paradise to Paterson, CA to my first MVCC meet, I had no problems with my M151A1. I did do some modifications back then that I felt were improvement. Restricting the rear A-Frames, a fuel return line, changing the transfer gear from those rollers to Tikum bearings and adding a fuel pump where the vacuum was. Did all this without this thing called internet.
Many thanks to Army Jeep Parts, Kirt Lesser and a number of others that has passed away.

I never had to take apart my carb. But I did add a fuel return line from the carb back to the fuel tank.
Made a big difference in performance and fuel mileage.

Man, I had fun back then. I drove that A1 from Paradise to Venture, CA all the way to Furndale, CA and all points in between. I never had any major problem except the points in the distributor. Paterson, Woodson Bridge, Big Bear Resort, I took that A1 all over the State.

Now I’m going to do it all again with this A2.

ldj1002
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Re: another carb question

Post by ldj1002 » Sun Mar 27, 2022 7:28 pm

Got carb together and it runs good in shop. Can't drive it till I get u-joints. Can I drive it creeping around the back yard with front drive shaft out?

Tech3140
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Re: another carb question

Post by Tech3140 » Sun Mar 27, 2022 7:31 pm

What did you find wrong ???
I would like to know.

Rickf
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Re: another carb question

Post by Rickf » Mon Mar 28, 2022 9:26 am

If you drive it with the drive shaft out you will take the chance of the yoke popping out of the transmission and dumping all of the oil out on the ground. Will not really hurt the transmission in the back yard but I can't say as much for the yard and the fact that you will now have to find the yoke and refill the transmission.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Rickf
G-Lieutenant General
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Posts: 5909
Joined: Sun Mar 19, 2006 10:04 am
Location: Pemberton, New Jersey

Re: another carb question

Post by Rickf » Mon Mar 28, 2022 9:27 am

Tech3140 wrote:
Sun Mar 27, 2022 7:25 pm
Ok, Maybe I got lucky. But way back in 1985 when I drove my M151A1 all the way from Paradise to Paterson, CA to my first MVCC meet, I had no problems with my M151A1. I did do some modifications back then that I felt were improvement. Restricting the rear A-Frames, a fuel return line, changing the transfer gear from those rollers to Tikum bearings and adding a fuel pump where the vacuum was. Did all this without this thing called internet.
Many thanks to Army Jeep Parts, Kirt Lesser and a number of others that has passed away.

I never had to take apart my carb. But I did add a fuel return line from the carb back to the fuel tank.
Made a big difference in performance and fuel mileage.

Man, I had fun back then. I drove that A1 from Paradise to Venture, CA all the way to Furndale, CA and all points in between. I never had any major problem except the points in the distributor. Paterson, Woodson Bridge, Big Bear Resort, I took that A1 all over the State.

Now I’m going to do it all again with this A2.
There is no such thing as a "fuel return line" on the 151 unless you modify the vapor return fitting on the 13660 carburetor. And if you do you will drop the fuel pressure going to the carb depending on how big you make the hole. But no matter how you do it it is not going to change your mileage unless you had flooding issues to begin with. It takes a certain amount of fuel to move a certain amount of weight a certain distance. That is physics.
The return line that is built into the 13660 series of carburetors is actually a vapor return line and was put there in an effort to prevent vapor lock. Considering they did this on a closed fuel system shackled by emissions equipment it was kind of a lost cause.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

ldj1002
G-Command Sergeant Major
G-Command Sergeant Major
Posts: 235
Joined: Fri Nov 14, 2008 5:38 am
Location: Central Texas

Re: another carb question

Post by ldj1002 » Mon Mar 28, 2022 4:14 pm

Rickf wrote:
Mon Mar 28, 2022 9:26 am
If you drive it with the drive shaft out you will take the chance of the yoke popping out of the transmission and dumping all of the oil out on the ground. Will not really hurt the transmission in the back yard but I can't say as much for the yard and the fact that you will now have to find the yoke and refill the transmission.
I did drive around back yard, very slow and all went well.


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