ZENITH 13660B QUESTION(S)

[SALTWATER COWBOY]

Greetings,

First time forum post...

I recently picked up my first Military vehicle, MUTT M151A2; I love it! Anyway, when I got it was told to run it with the choke out. It ran well but would stall out if choke wasn't used (1/2 to 3/4). So, I ordered a rebuild kit and cleaned it up and put new diaphragm in it and base gasket, etc. Since then, I've had it off several times (too many to count).

1. I pull the plug out the mixed screw and replaced with the new brass screw
2. I replaced the needle and seat (used the old one a couple of time too--Keeps sticking and not wanting to let fuel in bowl).
3 While running I checked for leaks, sprayed carb cleaner all around, no changes...

Problem now: It keeps flooding. I'm 99% sure the float is not set correctly. I'm going to put the new needle and seat back in even though it sticks while on the workbench (weird). Recently ran it around the block a few times and was perfect.Then hit 4 gear and it flooded at the light (gas coming out pulled back breather tube).

Question: Is the 9/32 setting without any pressure on the float? This seems critical to me based on it flooding now. When I put a little pressure the needle will still move slightly. With pressure I've had it at 9/32 but not without. It runs (ran) great but wanted to fix the choke issue...I haven't had it long enough to run a full tank of gas and not sure how long it sat idle before me (I did add non-ethanol gas to tank). The fuel tank filter (catch) seems dirty, so, I plan on cleaning the tank and getting it perfect to make sure source is solid.

Couple of closing items, cleaned up the carb. I didn't remove the long tube (one of only items left in). Everything flows cleanly. I didn't mess with shaft seals (didn't think necessary based on carb cleaner spray leak check while running). The carb seems to be in very good overall shape. Thanks, appreciate any feedback.

SaltWater Cowboy,
Cortez, Fl.

[captaincarrier]

Have you spoke with Billy Brooks in Clearwater?

[Rickf]

Well, Your float setting is correct but no pressure on the float. You did not lose the idle jet out of the bowl did you? They will fall right out if you are not careful. What fuel pump are you using and have you checked the fuel pressure at the carb? Anything more than 4lbs. and you are going to have flooding issues. Even with a stock engine mounted pump if the diaphragm get old and hard it can cause high pressure. Are you running the engine with the intake hose off? This will cause issues, usually lean running issues but also you have to keep in mind that with a vacuum operated accelerator pump as soon as you shut it down it will shoot a shot of gas into the throat of the carb and that shot of gas will run out of the mouth of the carb making it look like it flooded. I do rebuilds on these carbs but it sounds like you have that already covered. To eliminate the flat spot/choke running issue just set you idle mixture a hair on the rich side. Also be sure to be running a 180 degree thermostat instead of the stock 160 degree.

[SALTWATER COWBOY]

Have you spoke with Billy Brooks in Clearwater?

No, I haven't. Do you have contact information? Thanks...

[SALTWATER COWBOY]

Well, Your float setting is correct but no pressure on the float. You did not lose the idle jet out of the bowl did you? They will fall right out if you are not careful. What fuel pump are you using and have you checked the fuel pressure at the carb? Anything more than 4lbs. and you are going to have flooding issues. Even with a stock engine mounted pump if the diaphragm get old and hard it can cause high pressure. Are you running the engine with the intake hose off? This will cause issues, usually lean running issues but also you have to keep in mind that with a vacuum operated accelerator pump as soon as you shut it down it will shoot a shot of gas into the throat of the carb and that shot of gas will run out of the mouth of the carb making it look like it flooded. I do rebuilds on these carbs but it sounds like you have that already covered. To eliminate the flat spot/choke running issue just set you idle mixture a hair on the rich side. Also be sure to be running a 180 degree thermostat instead of the stock 160 degree.

Thanks for sharing all of this information. I am reading all of your post so I can learn about these engines, etc.; definetly an art...

It has the manual fuel pump. I haven't checked the fuel pressure; however, I made a better adjustment on the float and it is running quite well. It was a little out of adjustment. I drained and cleaned tank with new filter. I still have to run it with about 1/4 choke, it is the best it has been. I have kept the intake hose on too. Idle jet is good... I did all of this today. It is purring, I'm quite pleased. I like to fix things myself and learn. I don't have any vacuum leaks (flooding gone and running it's best since I've had it)...

I've done the basics has you have shared before, good spark and charge, connections clean, etc. I do need to do some replacement of fuel lines and misc.

What is best way to get a good carb as backup, ArmyJeepParts?? I would like to not have to run with 1/4 choke. I may be able to tune it out. I think my carb is really good condition, but now new...

I have some other questions on other MUTT items, but may make new post to keep things organized, I assume that is best way, Thanks Mr. Rickf...

[Rickf]

Your best bet on a used carb is the shows. If you want to buy a rebuilt one that is fine but a lot of money. I could rebuild yours for a lot less than buying one from AJP but to be honest, you seem like you know how to work on them so if you take your time and make sure it is soaked and cleaned out very well and then set the float to spec and set the idle just a hair rich you will have eliminated the flat spot. And the biggest way to get rid of the flat spot is a hotter thermostat! Go with a 180 thermostat and you will be amazed at how much better it runs. And no, it will not overheat.

[SALTWATER COWBOY]

I will double, triple check everything including the thermostat and work on little rich adjustment, thanks for your help and replies. I will follow up with any details that may help others, kind regards.