1950 SA-200 short hood welder
Vernon
generates current.
We got it started with a mystery Carter carburetor I bought on ebay.
It is an updraft type carburetor and the flange fits the engine
manifold. However, the linkage does not allow for hooking up either
the rod on the governor at the back of the magneto or for the rod that
goes to the vacuum diaphragm device.
Furthermore, we were not able to get any significant speed out of the
engine.
Nevertheless, it has decent oil pressure (about 25 at a hesitant rough
idle and doesn't smoke significantly.
Do any of y'all have an understanding of how the vacuum diaphragm, the
carburetor, and the governor interact with each other?
The vacuum diaphragm has a doodad on the bottom that looks sort of like
an ignition points capacitor. It is mounted behind the diaphragm and
has a broken wire. My son thought it was a mercury switch. But I
don't have a clue.
In any event it's broken. And I'm told that Lincoln obsoleted the
entire system long long ago.
Therefore, one of my first decisions will be what to do about the
carburetor and the idle system.
But I really don't even know what it does. Am I correct that these
systems automatically increase/decrease the engine speed as needed?
I'm still a long way from welding with it.
Thanks for any and all advice.
Vernon
Thomas Kendrick
engines in the MF 35, and MF 77 model tractors. (this information
found on another discussion board).
R. Zimmerman
not welding the engine would be at idle. When you struck up welding current
would activate a solenoid and pull the throttle open via the governor. When
you stopped welding the current stopped flowing and the solenoid would
release allowing the engine to idle. I am guessing your old system used
engine vacuum to pull the throttle.
In any case you can run the engine at governed speed and just weld. When
you stop welding the engine governor will maintain high idle. When run in
this manner the welding machine will burn a lot more fuel.
The problem with speed must be a carburettor problem. My guess your idle
circuits are working but your main jets are clogged or there is some other
form of fuel starvation. You might try choking the engine to see if the
speed instantly increases of decreases before it dies. If the engine runs
better with choke on or slightly speeds up then you have a fuel starvation
problem.
Just a side note: Down draft carburettors tend to promote fires in a
variety of situations. If the engine intake is flooded fuel vapour and gas
descends out of the carburettor especially if the air filter is removed. In
a downdraft situation the dangerous fluids and vapours fall into the engine
intake. Keep this in mind when fooling around with air filter off.
Randy
"Vernon" <vt...@tucklings.com> wrote in message
news:1149645326.5...@y43g2000cwc.googlegroups.com...
Vernon
Thank you very much for your usual spot-on-point comments.
My son was tinkering with the carburetor side today. And I continued
to be quite worried about a flashback fire. So your comments put that
issue squarely to the top of my priorities. i.e. safety.
I have a Donaldson air filter that came off an Allis Chalmers forklift
that has a Continental F163. I'm moderately sure it will work on the
welder.
But tell me this. When you strike an arc, whether at 20 amps or 200,
does the engine kick up to its governed speed limit of 1400rpm and then
fall back to idle or high idle when you break the arc?
As to the carburetor it is a Carter. However, a local welding guy was
stunned to learn that I had a Carter that would fit the welder. I
bought it on ebay. But I don't remember anything about it. I also
bought a Zenith that was SUPPOSED to be the upgrade model for the
SA-200 welder. And indeed, although the linkage looks quite similar to
the original Marvel Schebler carb, the mount stud spacing is bigger and
the carb won't mount on the intake.
I remember that disappointment right after I bought this welder about 5
years ago. However, at some point I bought the Carter carburetor. But
I can't remember a thing about it. In any case it appears to be a
brand new "old stock" carburetor. My son Mark, who has inherited his
mother's mechanical genius, has come to the same conclusion that you
do. I.e. that the engine is being starved for fuel. Tomorrow I'm
gonna let him call the shots. Every time I roll over and let him or
Queen Bee do things THEIR way, fur flies and shit happens.
If he can get the carb to feed the engine to 1400rpm and it runs good
and stays cool I'm off to weld up some fence.
By the way, can you tell me what that pin does when placed into the
vacuum idle system? It would appear to keep the diaphragm from
expanding or contracting.
Is that the high idle you're talking about?
V
R. Zimmerman
get the old girl to rev up before starting your weld. Better machines
responded fast enough that you could just start welding and the engine would
pickup the load. When you broke the arc the unit would drop back to low
idle.
At low idle the vacuum would high so the vacuum would act on the
diaphragm which would pull the throttle closed down to low idle. When the
arc is struck somehow the vacuum on the diaphragm is released or
discontinued. A spring pulls the linkage back the other way and opens the
throttle to allow the engine to run at high speed. This is just off the
wall. I haven't seen your particular system. That "pin" you mention likely
cuts off or opens the vacuum to the diaphragm.
If you can't get the control system to work then just leave it on high
idle.
Those old flat head Continentals are amazing. In modern times we make
things so complicated and sophisticated. The end result is that things die.
Those engines are almost indestructible.
The updraft carburettor is difficult to flood but.... great for starting
fires. Just a word to your offspring. Tell him you want to keep the
genetic line. :'))
Randy
"Vernon" <vt...@tucklings.com> wrote in message
news:1149655412.5...@h76g2000cwa.googlegroups.com...
bfr...@sbcglobal.net
I have a 1947 SA200 which is probably quite similar to yours. Those
are fine machines so don't give up on it. What you really need is the
original Marvel carb - they are available at Foley's
(www.foleyengines.com) as are most of the other parts you may need for
that F162 engine. The other day I saw a site (can't remember where - I
think I probably Googled "Lincoln SA200") that encouraged the use of
those old pipeline welders and sold a couple of upgrades - one was an
electronic version of the vacuum "rev-up" device that our old welders
have. The other two upgrade parts were an electronic ignition to
replace the magneto, and an air filter system that was represented to
be superior to the oil bath system that came with your machine. There
really isn't any reason to replace the magneto - parts are available
and they usually don't break. The rev-up device is another matter
because parts are hard to come by although they are fairly durable.
Unfortunately the electronic rev-up was about $400 but represented to
be the permanent end of all problems and much more responsive and
precise than the vacuum system.
Another great resource for information and parts (albeit expensive for
parts) is Lincoln itself. I bought my machine from the original owner
in 1996 and because it was so complete (even still had the decals and
the side panels) I wanted to restore it. I called Lincoln and spoke to
someone in their tech department who had been there 30 years or more -
he was quite friendly and interested in the old machine and very
helpful - to Lincoln the code and serial numbers are everything; the
code more than the S/N - I called back yesterday to learn that the
fellow that I had talked to 12 years ago had retired two weeks ago, but
the lady (Jamie Borkowski, if you want to call her) that helped me was
just as helpful. A great resource; also, Lincoln is quite interested
in those old machines and even the old style "Shield Arc" decals and
the face plate are available from another site (linked to the Lincoln
site).
Does your machine have a starter or is it a hand crank? Mine never had
a starter or ring gear - the regulars on this forum know of my somewhat
eccentric attempts to get around that problem including motorizing the
generator to start the engine (quite do-able), etc.
It's not hard to start if the carb is set up right - another benefit of
the magneto.
If you haven't been able to strike a strong arc, or get the machine to
rev-up to the 1400 rpm, you may have an exciter problem. Mine
developed such a problem; the symptoms are that when you attempt to
strike an arc, even if you short the stick, the engine won't rev up - I
was less knowledgeable then and simply took it to the Lincoln dealer
who fixed it. I messed around with the rev-up device but that wasn't
the problem at all. It had something to do with the exciter, but I
don't remember what - someone on this forum will know exactly.
One other thing that is important if you don't use the machine a lot -
put good filtering on the fuel line. Those systems tend to "gunk up"
with either rust or just shellac and other fuel crud. Mine is kept
outdoors in West Texas which is pretty dry so rust inside the tank
isn't much of a problem, but crud left by evaporating fuel is. There
are two holes in the bottom of the gas tank - one feeds the carb and
the other is just a drain, I suppose. Anyway, I put a valve on the
second hole and just drain the fuel when I'm not going to use the
machine for awhile and that pretty much ended the crud problems.
Stabil is a good fuel stabilizer for long term storage, but I don't
think it helps on the evaporation problem.
Good luck with that old machine - for stick welding it's about as good
as they get.
Bruce
Vernon
Good to hear from you!
Up to now we're running the thing with an old Carter updraft
carburetor. It fits the machine but the linkage will not accept the
rod from the vacuum bellows or the rod from the governer.
Therefore, I don't know what's working. Thanks to Randy's admonition
about the flash fire hazard of the updraft carburetor design my son is
over fishing for the Donaldson air filter I took off an Allis Chalmers
forklift that has an F163 engine.
If that air cleaner won't work I'll buy one from weldmart. That might
be the place you were looking at for the idle upgrade kit.
Where are you in Texas?
We live in Brenham.
Vernon
bfr...@sbcglobal.net
Weldmart is where I was talking about. I'm in Austin, but my welder is
on a ranch near Junction.
Bruce
Vernon
We used to hunt deer on a ranch northwest of Harper.
V
Vernon
This welder has a hand crank plus a 6 volt charging system and push
button start. I borrowed a new 8 volt battery from my Farmall Cub
tractor to start it with. The charging system on the tractor wasn't
working so the battery was a little flat. After briefly charging it
with a 12 v charger on the 2 amp setting (5 minutes at a time) I
abandoned it and set up a 12 v battery. I disconnected the generator
from the circuit.
Twelve volts spins it like an egg beater.
V
JTMcC
> By the way, can you tell me what that pin does when placed into the
> vacuum idle system? It would appear to keep the diaphragm from
> expanding or contracting.
>
> V
The little pin on the end of the little chain, when put thru the little hole
in the linkage pins the engine at high idle.
You really need to get a set of manuals, and the proper carb.
JTMcC.
Potblak
http://www.weldtron.com/products/idlers/Idler%20controls.htm
They have an aftermarket replacement for the idler control board for the
SA200.
"Vernon" <vt...@tucklings.com> wrote in message
news:1149645326.5...@y43g2000cwc.googlegroups.com...
Vernon
Your link was quite interesting.
V