The Johnson Iron Horse

By Staff
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Photo B: left to right, Model X436 hand start and X417 foot start wash machine model with long choke cable and flexible exhaust pipe.

2 Donnacona Crescent Scarborough, Ontario M1E 3P9

My interest in engines began about ten years ago when visiting
my sister in Milton, Ontario. It never seemed to fail that we
picked the Labor Day weekend for our visits when the Steam Era Show
was on. We could hear the steam whistles off in the distance, and I
was told about the steam show in progress. After a couple of years
I decided it was time to take a look for myself firsthand, and I
was amazed at all the activity going on. I thought it would be
great to own one of those engines.

I had always been somewhat mechanically inclined, so about five
years ago I decided to take a night school course in small engines.
Little did I know the bug had bitten. I started simply enough,
overhauling all the small engines in my possession. After the first
year I had run out of engines of my own, so I fixed a few for
friends the second year, but soon even these were in short supply.
By the third year I started buying any old engine I could find and
fixing it. About this time I was working on

Briggs, as these were the easiest to find. A friend said,
‘Why don’t you get a cast iron one to work on?’ Little
did I know it, but that old iron bug had me hooked after I finished
my first cast iron engine, a model 9 Briggs. I started to look for
something different, and that’s when I stumbled across the
Johnson Iron Horse. It sure looked different with its angled
cylinder and suction carburetor.

Well, now my collecting moved into high gear. Where would I find
these engines that have not been made for over 40 years? The first
year I found fifteen of them. Some were restorable and others would
be a future parts supply. Most of the engines still had their
engine tags attached, and this started the first of many puzzles
what did all the model numbers mean?

The answer to this question eluded me until one day, while I was
buying some Briggs parts, I asked the chap about Iron Horse
engines. I asked him if he had any manuals on these engines. He
did. He was kind enough to let me photocopy them. This not only
answered my first question about the model numbers but started my
collection of Iron Horse repair and parts manuals.

At this point I had to decide what direction this hobby would
lead. Would I steer to the big hit and miss which I had longed for,
or would I stay with the smaller engines? Living in the city
presents a space problem. I do have a double garage, but space is
at a premium, what with lawn mowers, bicycles, work bench and all
the other things one ac-cumulates. With this in mind, I decided to
go in the direction of the smaller engine. I could collect a wider
variety, store them easily, and (only having a car and trailer) I
could transport them to the shows with ease.

This brings me back to the Johnson Iron Horse: a simple little
engine but rugged enough to run with little attention. It is the
only four cycle engine made by Johnson. These engines were
assembled at Waukegan, Illinois, and at the Peterborough, Ontario,
factory. This engine seems to descend from their Utilimotor as a
compact dependable engine. To quote from one of their advertising
brochures they describe them this way: ‘Johnson Iron Horse
engines are available in two convenient sizes to develop either ?
or 1.34 horsepower. The dependable Iron Horse is widely used to
provide power at low cost for washing machines, lawn mowers,
pumping water, electrical generators and a host of other uses on
the farm, in garages, workshops or home.’

There were five basic models: X100, X200, X300, X400 and the
X500. These models could be also shown as X1, X2, X3, or X4. The
X100, X200, X300, X400 series all used a suction type carburetor
and the same 2? inch bore and a 1 inch stroke. The X500 series has
a gas tank mounted over the engine and a float carburetor. The bore
is increased to 2 inches and the stroke 1 inches. With this change
the horsepower is rated at 1.34- The one other combination used was
a 2 inch bore with the suction carburetor; this they rated a 1

This simple engine was also used on a series of generators. They
used the suction carburetor and the base became the gas tank
holding about a gallon of gas which enabled the engine to run for
many hours charging batteries. The Canadian army also used this
generator to charge their radio batteries during the Second World
War. This model featured a waterproof plug and ignition wire, air
cleaner and a protective cage.

I will try and describe some of the many differences of these
engines as the variations become complex. The length of a choke
cable or the size of pulley will create another model, so I will
keep these descriptions as simple and basic as possible, starting
with the X100, X200 and the X300. With these three models the
cylinder and crankcase were cast in one piece. The X200 and X300
used different suction carburetors. They all had the same starting
system, which was a foot starter or hand starter depending on the
model. All models utilized a mechanical governor.

With the X400 and X500 series the cylinder and crankcase were
cast separately. They also used different carburetors, one suction,
the other float. They shared numerous starter systems which include
two types of starter handles and five different-shaped foot
starters. They also had a recoil rope starter which I am told was a
first. A mechanical or air vane governor were also used, as was the
backup rope pulley starter. The generator sets could be started
with a battery or the rope pulley starter. I have tried to keep the
descriptions as accurate and simple as possible. My estimation is
that there are over 100 different models.

I now have five restored and fifteen restorable engines and many
parts engines which are essential in any restoring project. Five
generator sets, two Bob a Lawn lawnmowers that were made in Canada,
and one Evinrude Lawn Boy powered by an Iron Horse engine round out
my collection.

The main reason for me writing this article is the hope of
getting some more background material on this engine. It seems that
the history is very sketchy as to the exact year production started
and finished. I have been told that all the records at the
Peterborough plant were destroyed, and Waukegan had no records
either. Maybe somewhere out there someone who worked at either
plant has some vital information that could be passed along
answering so many questions about this engine. I would like to hear
from other Iron Horse collectors who may have information they
would like to share, or if I have made any mistakes I would like to
hear about them.

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