[Farmall] Well, I guess I didn't really want it to be easy

[Andy glines]

--- Dean Vinson <dean at vinsonfarm.net> wrote:

> Or I'd have bought one that was all restored and
> perfect.
> 
> Decided to take a vacation day today just to work on
> the tractor, and it's
> been a good day, if you define that as "getting to
> work on the tractor."
> Short version is that the 1950 Farmall M is still in
> my back yard, still
> won't start, and the problem now seems to be
> electrical:  no spark.   (It
> had a spark last week when I tested it, and when it
> started yesterday, but
> now I can't get anything.)
> 
> Tried to start it this morning to see if sitting
> overnight had fixed
> anything, but no luck.  A couple of folks had
> suggested trying some ether,
> but I didn't have any.  Tried some WD-40 into the
> air intake pipe on the
> carb, but no luck there either.
> 
> Gasoline looks okay to me, although maybe it's bad
> or watery and I can't see
> it.  Nothing noticeable in the sediment bowl, and
> when I open the drain plug
> on the carb and let it run out and collect in a pan
> it looks fine.  Flow
> rate seems fine.
> 
> I tested compression just to see what it was, and
> found that it's low in a
> couple of cylinders:  115 psi in #1, 118 psi in #2,
> but only 90 psi in #3
> and 105 in #4.  But that problem didn't suddenly pop
> up overnight and the
> tractor started easily before, so it doesn't seem
> like low compression could
> be the only problem.
> 
> (I guess 90 psi is low, since it's a lot lower than
> 115.  But does that mean
> that 115 is okay?  What's a reasonable range?)
> 
> Walt had suggested that low compression might be
> making it easy to flood,
> and the carb has been noticeably dripping gas after
> I choke it.  I don't
> normally choke unless it doesn't start on the first
> few cranks, but it
> hasn't been starting.  I took the air cleaner off so
> I could clean it and so
> I could see the air intake pipe on the carb.  After
> cranking the engine with
> the choke out (on), when I open the choke back up
> and stop cranking I can
> see gasoline literally running out the air intake
> pipe.  It stops after a
> few seconds, so I guess gasoline builds up against
> the inside of the choke
> butterfly while cranking, and then just runs out
> when I open it up.  
> 
> Rick had thought maybe the float was stuck, so I
> took the carb off and
> opened it up.  Float seems fine, but there was some
> watery brown crap in the
> bowl, looked like the same mess I'd cleaned out of
> the air cleaner cup
> yesterday.  (Cecil, looks like I owe you some shim
> stock).
> 
> Second thing I noticed was that the main adjusting
> screw wasn't even close
> to the seat, like about ten turns backed away from
> it, just the very tip of
> the needle sticking through the body of the
> carburetor.  It had evidently
> been that way a long time, since there was so much
> gunk built up around it
> that it wouldn't screw in any farther.  I had to
> take out the packing nut
> and clean the gunk out of the hole in the carb body
> with a little
> screwdriver.   I cleaned everything up as best I
> could and put it back
> together, closed the main adjusting screw all the
> way then opened it back up
> half a turn, and put it back on the tractor. 
> Cranked it over but still
> nothing.  Tried opening the main screw another half
> turn, but that didn't
> make any difference.  Same deal as before with
> gasoline accumulating behind
> the choke when I close it, then running out the air
> intake when I stop and
> open it back up.  Cranks over fine but not so much
> as a sputter.
> 
> By then Charlie had suggested putting a 12V battery
> in, which sounded like a
> good idea.  Cranks like hell now, which I kind of
> like, but still doesn't
> start.  I tried a few adjustments to the carb but
> nothing.  So okay, all
> kinds of cranking power, air and gas, but not even a
> sputter?  Back to
> electrical.  Went to look at the spark, just to see
> how they compared to the
> ones I saw on Sunday when I'd first run into the
> no-start problem and still
> had the 6V battery in.  Figured they'd be nice and
> big tonight with that 12V
> battery, but I couldn't get any at all.  Tried three
> of the four plugs, and
> nothing. 
> 
> Jumped a wire around the ignition switch, made sure
> polarity was correct at
> the coil, and re-checked plug wire order and grounds
> (thanks, Farmer, Mike,
> Jim, Lew, James... :-), but still nothing.
> 
> Rick has been patiently suggesting I replace the
> condenser, so that seems
> like next on the list.  Only trouble is I can't
> figure out how to get the
> distributor apart to get at it... as Jim had
> mentioned in a previous thread
> I guess I've got an after-market distributor since
> it's one of those
> 90-degree vertical drive units.  If that little
> plastic disc under the rotor
> lifts up out of there, I sure as heck couldn't see
> it.  I'll try again
> tomorrow... it has to come off somehow.
>> Dean Vinson
> Dayton, Ohio
> www.vinsonfarm.net
> 
Dean, I wouldn't worry about the compression those are
pretty OK numbers.  Ideally we like to see them closer
to equal.  Squirt some oil in the cylinder with 90psi
and see if it comes up.  If it does the rings are worn
it it stays about the same the valves may need some
work (make sure that they are properly adjusted). Your
description of the main jet is a little concerning but
I don't think that it is preventing start up.  If you
take the carb apart again blow out all of the passages
with compressed air and make sure that they are clear.
 If you get fuel out of the carb when you choke it it
should start.  Even though I suggested fuel the last
time I wrote I had a nagging feeling that you may not
have good spark.  Be careful with that 12v it may
cause your coil to have a very short life.  Use a 12V
coil with the 12V battery.  A system with a bad
condensor will produce a spark but it will be very
weak.  You need the spark to jump at least 1/4" in
open air.  Remeber, it takes more strength to jump the
gap under the compression in the cylinder.  A new
condensor is a good idea take the old one and the
numbers from the distributor to the store with you. 
The points are under the plastic disk that you
described.  It should pop out fairly easy after you
pull the rotor off.  You may need to do a little light
prying with a screwdriver.  Inspect the points and
clean, adjust, replace as needed.  If you have not put
new sparkplugs in do it.  I have seen many a plug that
looks "good" but is bad.  Someone here will suggest
the proper plug for your tractor.  Don't rely on it
having the correct ones.  

Andy Glines
Evansville, IN

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