Re: [MV] M151 carb - update

From: Mil-Veh Co. (milveh@sbcglobal.net)
Date: Wed Feb 23 2005 - 09:30:00 PST


I just took it apart again and checked it over. Some
black gritty dry stuff fell near the needle valve, (2
sand size pieces of grit) so it could be the needle
valve was not seating properly. I've since blown it
out again, probed it and all seems clear as far as I
can tell.

Unfortunately, I didn't see exactly where that grit
came from when I dumped it out, just sorta fell out
into my hand when I tapped with float/valve out, but
obviously whatever it was it should not have been in
there. That's a good clue for you guys, ALWAYS take a
real good look first before dumping it or air
blasting, just see where the problem might have been.

I am running a new fuel filter, so I suspect this
gritty junk could have been residue that somehow
didn't get blown out from the recent rebuild I did and
worked its way towards the float area.

Next: Ah, so engine vacuum is key to operation, good
to know. I'll double check my lines one more time,
but I believe they are all 100% air tight.

With all my Mutt manuals (1600+ pages, 7 manuals) they
say nothing about how to rebuild the dang carb., only
how to replace it. Would have thought the military
would have said that, but I sure can't find it.

Thanks for tips MM!
  
--- muttmeister@rawfire.torche.com wrote:

>
> Jack,
> The MUTT carbs don't squirt, but they'll drip.
>
> The accelerating pump is vacuum operated so that the
> carb can be
> submerged in water and still work. Engine vacuum
> holds a spring
> compressed then when you step on the gas the engine
> vacuum drops so the
> spring releases against a diaphragm that operates
> the accelerating pump.
> Clever huh! Thanks to Carter carburetors.
>
> As for the drip.... when I shut any of my three
> MUTTS off I always see a
> few drips of fuel out of the carb. I've discussed
> the problem with
> other MUTTer's and we think that is over flow from
> the float chamber.
>
> I have repaired many MUTT carbs by disassembling
> them then soaking 'em
> in carb cleaner over night. After a though washing
> I blow out all the
> chambers with shop air then poke whatever will fit
> (wire, drills, pipe
> cleaners) into all of the orifices to make sure that
> they are clear.
> Usually I just reassemble the carb with all of the
> original parts.
> Carefully check the diaphragm for cracks and the
> needle valve for a
> ridge around the tip. The ridge on the tip will
> cause the valve to
> stick closed. If there's a ridge I polish it out
> using a fine Scotch
> brite pad.
>
> MM
>
>
> On Tue, 22 Feb 2005 17:52:07 -0800 (PST), you wrote:
> >I noticed that when pumping the carb before
> starting,
> >no fuel is squirting out into the venturi area.
> >
> >Normally, I would know what the problem is, but I
> >don't quite understand what's up on this Zenith?
> >
> >Any ideas, suggestions or wanna sell me nuther
> carb?
> >lol
> >
> >Thanks in advance... Jack
> >
>
>



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