M151 NOS carb question

[pharbor1941]

I recently purchased a supposedly NOS carb for the M151. After receiving the carb, I found that it is not marked with the Zenith name or production date, only a part number where the Zenith name is usually located. My main concern is with the screws that hold the butterfly valves to the shafts on both the choke and throttle. Neither appear to be staked or crimped on the threads to prevent the screws from backing out. I also noticed that the idle adjusting screw does not properly "seat" on the choke lever. When the screw rests on the lever, only the edge of the screw contacts the lever instead of the full face of the screw. Does anyone have any info on these carbs? Are these actually late NOS military replacement carbs or reproduction?

[pharbor1941]

Here is picture of carb

[homerguy]

From Delaware Lister by chance? If so it came from Murray's

[Rainman]

I have 2 of these, and have been running one for 2 years at least. Mine worked straight out of the box. Runs good for parades at first gear idle, and on the highway at 55. We had a thread on this not too long ago, but I'm in position to search for at currently. They are expensive repro's in my opinion, but have never heard of any problem with them. When I bought the first one, kinda like you, I didn't know it wasn't NOS Zenith. I knowingly bought one the second time. I'm not the only one here that runs one, but I'll let them confess if they choose.
Rainman

[rickf]

Delaware Lister is not Murray. He does all of the E-bay listing for KC Gonzo. I have one of those carbs on my mutt and I bought another to have as a spare. They run exceptionally well. They are the last carbs made for the M-151. I do not know if any were actually used in this country since the 151's were shipped overseas. The carb is exactly the same as the Zenith with the exception of the external idle mixture screw.

Rick

[pharbor1941]

Thanks for the information. Sounds like it should be fine. My biggest issue was with the screws not being staked in placed on the butterfly valves. I can resolve that issue myself.

[rickf]

I am pretty sure you will find small star washers under the screws. When I rebuild carbs I do not stake the screws mostly because there is not enough screw left after filing the previous stake off. I just use blue locktite.


Rick

[pharbor1941]

I used Loctite on the butterfly valve screws and peened the screws threads that projected on the back side. I used a spring loaded center punch on the threaded section that extended out the back side. There was just enough sticking out to deform a few threads. I closed the idle mixture screw and backed it out 2 1/2 turns and started the engine. Only had to make a slight adjustment to the idle screw. It runs great.