[AT] Never Heard Such a Bang!

[Whittaker Gregory]

Bad condenser.

On 2/27/2013 9:19 PM, Ben Wagner wrote:
> Hello,
>
> It's been awhile since I've had to ask a question on here. Incidentally,
> the question is on the tractor I was always bothering everyone about a
> few years ago, my 1948 Farmall Super A.  Since that restoration, I have
> completed restoring/rebuilding everything from Gravely walk behinds, to
> Clinton equipped lawn mowers, to Ford tractors, and now even John Deere
> two cylinders.
>
> All of that to say is even after all of that antique repair work, I am
> stumped on my Super A once again.  It's a long story: bear with me and
> maybe I'll give the right information that will help someone diagnose
> the problem.
>
> About a week ago, the Super A had been running for about 20 minutes.  I
> had it pushing in a John Deere M that I was rebuilding. I stopped to
> kick the block from under the Deere, while the Super A was running about
> 3/4 throttle, with a snow blade, so there was load on the Touch
> Control.  I got back on the A, and gave it a little throttle to push the
> Deere.  From the three seconds I had gotten off and back on the Farmall,
> it suddenly had no power.  As in nearly stalling while moving in first
> gear down a slope.  I cut it off and replaced the D21 plugs with fresh.
> It ran much better, well enough to push in the Deere (which was quite a
> load) and even scurry down the road in high gear.  It was still
> sputtering slightly, but it had power.
>
> I pulled the Farmall out a day ago to (once again) move a tractor. It
> started immediately, I am hand cranking, but it had no power, once
> again.  It died while I was trying to ease it into an area where I could
> work on it.   It wouldn't start back up.
>
> I tried to start it today, cold, and all I got after four hand cranks
> (choke at 1/2 like always) was one loud bang in the muffler/manifold.
> Enough to loosen the muffler from the exhaust pipe!  No backfire, but
> just one loud bang.  The engine didn't even try to start.
>
> I have checked timing.  Everything is in tip top shape.  All the valves
> are free and adjusted properly.  The carburetor is spotless: good fuel
> flow, no junk in the lines, clean jets.  It is a Zenith with no high
> speed adjustments.
>
> So the question is, what does the problem seem to be?  I have worked on
> quite a few engines (but not as many as the folks on this list) but I've
> never heard such a bang without a hot engine and too much choke!
>
> Thanks in advance for your help!
>
> Ben Wagner
>