Military trader/vehicles Magazine

[Redlight]

In the most recent issue of the combined magazine, there was a question and answer regarding a M151. The owner had a problem starting after 3 days. He said that the accelerator pump in the carburetor was not working. The column writer went on to describe how the check the pump, carb, etc.
Please correct me if I am wrong, but it is my understanding that the M151 has no accelerator pump and you need to use a bit of choke if it has not been run in a few day?
Comments please.

Redlight
M151
M416
M416 28 each (sold in retirement)

[m3a1]

Yeah....no accelerator pump. Some fellow is regurgitating some falsehood (something we all have to be careful with, right?) and it has no accelerator pump in the modern sense of the term. Effectively, it's just a big lawnmower carb. Rick can describe it far better than I.

Cheers,
TJ

[buzzinduzzin]

I believe it has a vacuum operated accel. pump , so pumping the pedal to substitute pulling the choke when starting is not going to work

[Mark]

My 151 had a Holley carburetor, my A2 had a zenith on it.I read somewhere the Holley is the Cadillac of carburetors so I replaced the zenith with a Holley.Then later on I put the zenith on, it leaked very bad, R&R with Holley.Lot of black smoke with Holley when tromping down on foot feed, gradually pushing foot feed, not much smoke.

[svramselaar]

Hi
The zenith has a vacuum actuated acseleration pump
The membranen is suckt back with the intake vacuüm (little trottle high vacuüm )
It suckt feul at the pump chamber
If yovu put the pedaal to the metal (trottle Valve open low vacuüm )
The spring push the the chamber empty to the intake
If the engine is standing idle the chamber is full
If stop the engine the vacuüm is gone spring Push feul to intake
So this is the feul you see at the airfilter Side
If the membrane has a leak the engine runs rich
It sucks feul trough the membrane to the intake

George

[rickf]

The M-151 Zenith carburetor DOES have an accelerator pump. It is vacuum operated as George said. What these people are spouting off is because they can not figure out that just because pumping the gas pedal does not inject gas when it is not running does NOT mean that there is no pump. I am utterly amazed that that kind of garbage can make it into a magazine with major circulation. That is the kind of knowledge you see spouted on Facebook by the keyboard mechanics that have never touched a wrench in their lives and all they do is repeat what they have read somewhere. I have rebuilt probably a hundred of them, and yes, they do have an accelerator pump.

And since Mark brought up the Holley carb, the accelerator pump on the Holley carb is a mechanical design and it works directly off of the linkage so pumping that one with the engine off WILL flood the engine. BUT, The Holley is no better than the Zenith as far as how they run. I have five left if anyone wants to buy one.

[m3a1]

...but does it actually pump? I think the use of that particular word is the hang-up.

Annnnnd....I answered my own question with a visit to Merriam Webster and OMG! .....Rick is RIGHT...... Again!

(that's a Rick Roll, by the way)

: a device that raises, transfers, delivers, or compresses fluids or that attenuates gases especially by suction or pressure or both

Rick Is Right ...Again... Merit Badge - AWARDED!

That's the SECOND merit badge awarded to other members of the forum..

Cheers,
TJ

[svramselaar]

hi
i found two drawings of the carb
the first one has the acselerator spring at the right side of the membrane
sorry for the two the same picture`s below
the lower one has the spring at the wrong side of the membrane
there the spring can empty the pump chamber

images.jpg

images.jpg

Admin edit, below is the WRONG spring position as noted.