Flywheel Forum

By Staff
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39/8/1: Unknown Briggs-powered mower looks to be homemade.
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39/8/3A: Unknown mower engine has a Toro nameplate, but Toro claims no knowledge of this unit.
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39/8/3B: Unknown mower engine has a Toro nameplate, but Toro claims no knowledge of this unit.
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39/8/1: Briggs & Stratton LA One of my
in-laws found this so-called lawn mower in an old building on a
farmstead he recently purchased. I would appreciate any information
any of your readers could contribute. The engine is a Briggs &
Stratton Model LA, engine no. 37331. According to information
available to me, the engine was built between 1931 and 1932.

Any information on the mower would be very much appreciated.
Harlan Ternes, 5335 Fair hill Road, Bismarck, ND 58503-8019; (701)

A: We’re betting the mower is a home-built
unit. That said, the addition of a transmission (we’re assuming
it’s geared to increase blade speed) is interesting.

39/8/2: Maytag Fuel Mixture? I have been told
that chainsaw fuel mix should not be used for Maytag engines. I
understand that non-detergent engine oil and gasoline should be
mixed, instead.

What mix ratio of oil to gasoline should be used? Also, what
weight of oil is recommended? Ron Shipley, 1110 Riley Ave.,
Emporia, KS 66801.

A: Good question. We’ve seen references
ranging from 1/2-pint regular oil to 1 -pint regular oil (not
two-stroke) per gallon of gas. Maytag owners?

39/8/3: Unknown Toro Engine? I’m sending
along some pictures of a one-cylinder gas engine of unknown

It has a Bosch AB33 magneto, a Tillotson clamp-on carburetor, a
brass petcock in the upper part of the cylinder as a compression
release and external valve springs with adjustable tappets.

It has no governor at all and must just depend on the
operator’s good sense not to let it over speed. It is
air-cooled and has a 6-inch-diameter pulley on the flywheel side
with a notch in it to wind a rope for starting. The crankshaft does
not protrude on the other side. It has a stub shaft that bolts to
the end of the camshaft as a power take-off (1/2-speed).

From what I can tell, it had never been repainted or taken apart
until I partially disassembled it for cleaning. Other than a
cleaning, I have left it looking exactly the way I found it.

I have shown it at shows, and it has generated a lot of
curiosity and a lot of questions that I can’t answer.

It has a brass tag on it that reads: ‘Engine no. 2639 Toro
tractors and golf course mowers.’

I contacted the Toro Co. in Bloomington, Minn., and they said
they had no records of ever manufacturing engines of their own.
Most of the engines they used were built by Lauson. I contacted
Lauson, and they said they couldn’t help. They don’t think
they ever made engines like this. Any help as far as history, use
and quantities manufactured would be appreciated. I picked this
engine out of the iron pile at a local junkyard for $10. All I did
was rebuild the magneto and clean up the engine, and it runs great.
They are still out there, if you look for them! Doug Oldenburg, 530
230th St., Homer, NE 68030.

Flywheel Forum is a place for readers to ask questions and share
information on their equipment. If you have a question about your
engine or tractor, please send it along to Gas Engine Magazine,
1503 S.W. 42nd St., Topeka, KS 66609-1265.

Modeler’s Corner

Following Through

By Rusty Hopper

Hello again everyone. As some of you may already know, on May
18, 2004, we lost a great model maker – Bob Shores.

I had recently been in contact with Bob, who was getting me some
of his drawings and plans for a new carburetor he built just before
his passing.

The carburetor Bob designed is called the ‘Minimix.’
Designed for model engines, it’s made from bar stock and is a
mechanically self-compensating, rotary drum, throttle-type
carburetor with only five parts.

I also had just purchased his book, Ignition Coilsand Magnetos in Miniature, which should be in every
modeler’s library.

Bob’s wife, Margaret, and his family will continue offering
his many fine model casting kits and his book. Contact them at:
Small Gas Engines 108CarmelinaSt, Ruskin, FL 33570, (813)
645-8322, 1/index.htm

New Directions

Editor Richard Backus and I had another talk about my input into
the magazine and how and where my column should be headed. We like
the tips and ideas many of you have sent, and we look forward to
hearing more from all of you. And don’t forget to send in
pictures of your model projects with a short write up about

I would like to use some of this space for a model-building
‘follow along’ where I build a model and describe the
process, discussing how well the plans and drawings read out and
the ease or difficulty of building a given model. This would cover
everything from the time of ordering castings to the first

The first model to get this treatment would be an easy-to-build
gas engine from a kit. Next up might be a steam engine, followed by
a conversion of some sort (turning an old air compressor into an
engine, for instance). Future build-ups could even include hot air
engines and multi-cylinder engines, and projects could be anything
from the newest scale on the market to one that has been out for
some time. Is this hobby great or what?

This month’s tips for model and scale parts sources:

Joe M. Tochtrop has a model of the Economy Engine. (415)

Jerry E. Howell has casting kits for hot-air engines and plans
for engines. (719) 579-6407.

These tips are for your thoughts only, and your fuel lines may

Have a tip other model makers should know? Send it to Rusty
Hopper at Gas Engine Magazine, 1503 S.W. 42nd St., Topeka,
KS 66609-1265;

From Rusty’s Mail Bag: Tips on Painting

I enjoyed your article on painting models, and I would like to
share some of my painting experiences in the hopes of helping you
avoid what sounds like a very frustrating experience.

First of all, any attempt to use any commercial spray paint
other than Krylon has, in my experience at least, led to
disappointment. The extra $1.50 a can for Krylon is well worth

Priming the metal is all-important – you absolutely have to have
a solid foundation, or your finish is destined for failure. And
before applying primer you must degrease the surface to be painted,
either with Coleman lantern fuel or 99-percent isopropyl alcohol. I
have had very good results with the ‘rusty metal’ primers
from both Rustoleum and Krylon. And forget what the label says:
Think in terms of days between coats, not hours. Here in Texas, I
like to let painted items bake in the hot sun for a day or two (a
couple of weeks is even better) after priming.

My favorite method for priming bare cast iron is to take it to
the car wash (or dishwasher if the item is small) to thoroughly
clean it, then let it sit out in the morning dew a few days to
lightly rust. Wire away any powdery rust with old denim rags, then
apply Permatex ‘Extend’ or any of the other high-quality
rust converters containing phosphoric acid, which turns the rust
black. This produces a very tough primer that is probably better
than any you can spray on. Again, adequate drying time between
coats or between primer and topcoat is essential, especially if the
primer and paint are not the same brand.

In regards to paint applications, yes, the spray equipment makes
a huge difference. For small work such as you are describing, you
will obtain much better results with an airbrush than a larger
spray gun.

Again, apply several thin coats, allowing adequate drying time
between coats, and use an inline filter on the air line to prevent
contamination of the paint stream.

For larger models or engines, try an HVLP (high-volume,
low-pressure) spray gun. Choose one that has a fluid-transfer
capacity of no more than 1- to 3-cubic-inches per minute (17- to
50-cubic-centimeters per minute). You will get much better results
with a small-volume-capacity gun operating near capacity than with
a larger gun choked down to nothing. Anything labeled ‘for all
types of paint’ or ‘excellent for latex paint’ is made
for painting barns, not engines.

Finally, I like to paint outside with a moderate wind blowing
toward the surface I am painting. This helps to carry the paint in
the right direction and helps it dry before it can run.

Once you get a coat of paint (I am assuming you are using
enamel) that you are happy with, you can dry it to a hard, durable
finish in your oven set at 200 to 250 F for one to three days.
Don’t do this with tanks that have ever held fuel! I keep the
stove vent hood going until all the fumes subside. This is also a
good way to speed up drying time if you are in a hurry, and the
parts are small.

You mentioned that you are having trouble with paint causing
valves, etc., to stick. Simply mask the parts you don’t want
painted with heavy grease and wipe it off (paint and all) after the
paint dries

I hope some of these tips help. I am only an expert on my own
experiences, but these tips have all worked for me. Keep that old
iron looking and running great!

John Townsend IV 15292 Fm2728, Terrell, TX 75161

Reader’s Scale Engines

These two scale engines come from the workshop of Australian
scale-engine builder Reg Ingold.

The engine above is a 1/4-scale 1885 Atkinson
‘differential’ engine. A four-cycle design, the
Atkinson’s seemingly convoluted linkage enabled it to run
through all four cycles in one crankshaft revolution. A fabulous
animated illustration of this unique engine (and many others) can
be found on the Web at

At right is Reg’s 1/2-scale Mottershead. It’s believed
the David Mottershead Co., Manchester, England, was in business for
only a year or so about 1910. Reg recently restored the only known
full-size Mottershead for an Australian collector.

Contact Reg Ingold at: 37 Seaham St., Holmesville 2286, NSW,
Australia; Check out some of Reg
Ingold’s other scales at:

Gas Engine Magazine
Gas Engine Magazine
Preserving the History of Internal Combustion Engines