Gas Engine Magazine

A Cub Comes Out Of Hibernation

By Staff

1841 Pinecove Drive, San Luis Obispo, CA

This tale has its beginning about 3 years ago in the lab at the
college where I teach electronics. It was during a break and I was
busying myself cleaning the place up a bit. Gabe came in. Now Gabe
needs some introduction but I’m not going into detail at this
time for he needs more than just an introduction; he needs a whole
story. Perhaps I will come up with that one at a later date. For
now, suffice to say that Gabe is the local ‘Mr. Engine’
around here. He has the unique talent of being able to see just
what needs to be done to make a recalcitrant engine run. He can
visualize what a missing part must look like and, most of the time
comes up with something approaching the exact duplicate. Mainly,
for the purposes of this narration, he is my main engine scout. I
have several engines and about half of them came, one way or
another, through Gabe.

On the day in question, Gabe showed up at the lab during my
break and said, ‘You still looking for a small engine?’ I
responded that by now he should be well aware that I was always
looking for a small engine. ‘Well,’ he said, ‘I think
I’ve found one you will be interested in’. ‘Oh
yeah’, I said, ‘What have you got?’ ‘Well’, he
said, ‘I haven’t actually got it, it’s just like I know
where it is.’ ‘O.K.’ I said, ‘Where is it and what
is it?’ So he said, ‘I just wanted to know if you were
interested first before I got myself involved.’

If you think all of this conversation is getting boring it’s
just because you don’t know Gabe. You have to do a lot of
verbal sparring with him before you get down to brass tacks and
then you must be wary lest the brass tacks turn out to be ten penny
nails. So I decided to go along with the drift of things and find
out what was going on in his head. ‘O.K.’ I said,
‘I’m interested so what have you found?’
‘Well’, he said, ‘this guy has two engines out in a
shed, they’ve been there for years but they’ve been under
cover all the time. One of them is big, maybe 5 horse power and
I’ve got my eye on that one but the other one is small and I
think it is just what you’ve been looking for.’ ‘So
O.K.’, I said, ‘What is this little gem anyway?’
‘Looks to me like a Cushman Cub. If it’s not, it’s
something very much like it and about the same size. Thing is,’
he said, ‘this is really a clean engine that looks like all you
need to do is fuel it up, crank it and away she goes.’

‘How much is it going to take to liberate this paragon of
machine-hood?’ He quoted me a figure that was a little higher
but not that far out of range of what I’d had to give up for
some other more or less seedy engines I’d already found through
hm. ‘So,’ I said, ‘Do you think it’s worth that
much?’ ‘Oh yeah,’ he said, ‘I’m telling you
this is really a clean machine you don’t have hardly anything
to do to it to have it ready for the show on Memorial Day.’
(Our local crew get together on Memorial day each year and hold a
fun time old engine show over in Cayucos at a place called the
Weigh Station because that’s what it used to be in old days.
Now it is a restaurant and the owners are very gracious about
sponsoring this annual event in their parking lot.) I thought it
would be really great to have a new engine to show that year and
since it seemed like this one would not be too tough to get ready,
I peeled out some bucks and turned them over to Gabe.

A couple of days later, Gabe showed up with the little gem. I
immediately realized how it was that he was not sure whether it was
a Cub or not. Through all the rust it was hard to be sure that it
was actually an engine! ‘This is the Cream Puff engine that you
described to me?’ I demanded. ‘Well’ said Gabe, ‘It
was pretty dark in that shed. Anyway, it’s not as bad as it
might seem, that engine is all there.’ ‘How can you tell?
For crying out loud, the only thing you can be sure of is that all
the rust is there,’ I said. ‘Yeah,’ he said, ‘but
look at it this way, if there is rust, there had to be something
underneath to support the stuff.’ ‘You told me all it
needed was gas and it was ready to go’ I said. ‘Well, I
guess I was wrong’ he said. ‘And I’m supposed to have
this thing ready for the show? You’ve got to be kidding.’ I
said. ‘Don’t feel picked on,’ he retorted, ‘the
other one is the same way and I’m going to get it in shape in
nothing flat, just you watch.’

By this time I had begun to pick and poke at the lump of rust
that sat there on the floor and, as the chunks of mud broke free
and the scales of rust were brushed away, it appeared that indeed,
this was a Cushman Cub and, moreover, it was, at least essentially,
all there. Trouble was everything was stuck firmly together with
that world’s greatest weld, ‘iron oxide’. The valves
were frozen in their guides. The piston, if there was one in there
was seized fast. There was a wierd growth in the mouth of the mixer
which was the only part of the  engine except for the mag that
was not iron but some kind of zinc or pot metal. There stood
bravely above all of this brown crud the square box-like structure
that was unmistakeably a WICO EK. It was not brown, it was green. I
said, ‘Gabe, you rascal, you have ripped me off.’ Not at
all,’ he said, ‘you can make a really neat little engine
out of this, and I’ve got another Cub for a parts engine that
you can have.’.’O.K., O.K.’ I said, ‘let’s see
how things turn out before I wring your neck.’ Which is
laughable in the extreme, I probably couldn’t get my belt
around Gabe’s neck, let alone my hands.

Don’t get the wrong idea about Gabe. He is not a dishonest
guy. You could trust him with your wallet or your wife but not your
knife. It usually goes something like this: You’ll be working
with Gabe on some kind of a joint project and he’ll ask to use
your knife. Instead of giving it back to you when he is through,
he’ll slip it into his pocket. If you are not alert and
don’t demand it back, he will hang on to it until he has shown
practically everyone in the county that he has your knife. Then
he’ll give it back to you. But, keep your wits about you
because in thirty minutes he will be working the same scam all over
again or something like it. You see, that’s just the way Gabe
is. On the other hand he’ll give you anything that he’s got
that you need.

With Gabe’s assurance that he would help whenever I got
stuck, I was mollified and, I have to admit, I was rather taken
with the compact little engine. Gabe was right in that part at
least, it was just about what I had been looking for in the way of
a small engine. A considerable improvement over my Sattley that
weighs in at about three hernias. So, shortly, work got underway.
The engine had to be stripped down to all of it’s individual,
constituent parts. Nearly every piece had to be sandblasted. Valves
had to be driven out of the guides with a mallet. The internal
mechanisms were in relatively good shape, having been more or less
preserved in a black gooey substance that resembled more than
anything else the material I use to coat my asphalt driveway. I was
worried about freeing up the piston but that turned out to be a
minor matter it was merely glued in place with this tar-like
substance. A little solvent and it came out O.K. The rings were
welded into the grooves with tar and carbon and rust and varnish
and stuff. I spent an entire afternoon freeing up the rings,
cleaning the grooves and fitting a replacement set of rings that I
made Gabe produce for me.

I swabbed out the cylinder about a hundred times with every
solvent I could find that wasn’t toxic and a few that I had
some doubts about. It finally began to look like an engine
cylinder. I worked it over pretty good with a hone and miked it
out. It had some little taper but I thought it to be in tolerence
and decided to stay with it rather than go for a rebore and the
accompanying complications with pistons and rings that would
necessarily follow that action.

The water hopper was half full of sand, gravel and broken glass.
It looked like this engine had spent some time on the bottom of a
stream. I had the devil’s own time getting all of those bits
and pieces out of the castings. Some bits refused to come out
through the top yet they were too large to fit through the water
channel holes leading to the head. In some cases I had to resort to
using long nose pliers to break the rocks or glass pieces into
small enough parts to fit through the orifices. This, and flushing
with a strong flow of clean water eventually cleared the engine of
that foreign matter. Then I had to make a new head gasket using the
old damaged one as a pattern.

Dismantling and sand-blasting was done to see what good shape
everything was actually in. The engine had come apart without
breaking any bolt, nut or screw. The only items that were missing
were the cover for the exhaust valve tappet and the lock screw for
the mixer. Everything else was there. Fortunately valves from
Gabe’s parts engine fit just fine which is a good deal, because
virtually nothing else from that engine fit. The condition of the
engine didn’t leave a clue as to what the original color was.
From a scrap of the parts engine we were able to determine that a
grayish blue was in order. I found a paint chip that matched almost
exactly, bought the paint and painted all of the parts. When the
paint dried it turned out that the finish was more on the blue side
than on the gray side. Not to worry, that’s the color this
particular Cushman Cub is going to be, a least for a while.

At this juncture in the restoration game, fate stepped in and
the press of business kept me away from the project for almost a
full year. I was out of town over the Memorial Day weekend and
missed the show entirely that year. The painted parts got
distributed over a fairly wide area though all in the same room.
When time once more permitted me to involve myself in old engine
activities and spurred on by a particularly enjoyable two day
session at the Cayucos show over the Memorial Day weekend the
following year, I decided to round up all of the pieces and see if
I couldn’t get the little Cub put together. Fate smiled. I
found everything in the storeroom, loaded it into my car trunk and
hauled it home. I had, up to this time, been trying to work on the
project in my ‘spare time’ in the school lab. This was a
mistake because everyone always knew exactly where I was and
interruptions were more a part of the activity than was the engine
project. With the engine at home during vacation, I could work
without fear of being called to the phone or asked to go to the
Dean’s office for this and that.

It took two days to get everything bolted back to where it was
supposed to be. Once it was reassembled, with the new blue paint
job the engine began to look as Gabe had predicted some months
previous, ‘Pretty Neat’. The question was, could it be made
to run? The mag was checked for spark and did a good job. Actually
the mag was the cleanest part on the whole engine and seemed to be
in good shape from the start, though it took a lot of elbow grease
to get the brass to look like brass instead of an old army, OD
paint job. Anyway, the ignition timing was set in accordance with
the manufacturers recommendations. The punch marks on the valve
timing gears had been checked at the time of reassembly and the
valve tappet clearance was set to specs. The oil pan and the gas
tank were serviced and, with a brisk rubbing of hands I prepared to
make the thing run. So I cranked it and nothing happened. I
rechecked and reset the timing and the valve clearance. Still
nothing! Once in a while, during the cranking process the engine
would fire but not with anything you could call enthusiasm. It
would never carry through even to a second cycle. Oh well!
let’s readjust the fuel needle valve and try again. Now I guess
I’ve got the fool thing flooded. So, once more, all of the
adjustments were reset and still the engine refused to run. I
remembered that someplace among my bits and pieces I had a spark
plug that, although it looked good, did not operate when under
compression. That must be it, I’d put the bad plug into this
engine. So I borrowed a plug from a friend’s International
Harvester that I knew had been running. With this plug installed in
the Cub I tried again. Still the same. The engine would not run! I
began to doubt those things I used to consider to be facts about
the theory of operation of the internal combustion engine. I
remembered reading in ‘Reflections’, some comment to the
effect that the timing marks on the valve gears could be set off a
bit and the engine could run even better sometimes. I began to
wonder…may be I needed to open the engine again and set the valve
timing to a different position? But set it where? It was already
where all of the theory said it should be??? Then, as I lay in bed
one night a thought came to me. Maybe I was looking at the wrong
end of the problem. I could have some carburetor problem here. Or,
to be more accurate a problem with the ‘mixer’. When the
engine was reassembled, I noted that the pot-metal casting of the
mixer seemed to have shrunk over the years and it threaded into the
head of the engine in a very loose fitting manner. So maybe, just
maybe, the engine was sucking air around those loose threads and
not drawing through the mixer throat as it should do? It took a
good bit of self discipline and contemplation of the things my wife
might say to keep me from jumping out of bed right there and then
and rushing out to the garage to try this new theory. Also it was
well past midnight and I might have incurred the wrath of the
neighbors, particularly if I was successful. So I went off to sleep
determined to get at the job first thing in the morning.

First I had to find some teflon tape of the type that plumbers
use on pipes to seal the threads so they would be airtight. When I
checked the tightness of the threads, I found that if I screwed the
mixer in as far as it would go it ended up on its’ side and the
gas line could not be connected and the throttle linkage would not
connect properly even if the air flow in that position could be
O.K. While working with the mixer I discovered that the face of the
air valve which I had taken to be some sort of bakelite was
actually practically petrified leather. Moreover, the seat of the
valve was pitted and scarred so that proper seating was impossible
even if the valve had been good. I rigged up an emory paper disc
glued to a small brass gear on a shaft. The gear, another piece out
of a junked radio, was just the correct diameter and the shaft fit
the chuck of my quarter inch drill. With this rig I carefully
restored the valve seat in the mixer so it was smooth and flat. The
valve itself was more of a challenge because not only was the
leather hard and brittle, the nut holding the entire assembly
together was firmly rusted in place. I put the whole business to
soak in a pan of penetrating oil. But impatience goaded me into
constructing a whole new valve assembly. I found a large washer
about one and one quarter inch in diameter and drilled out the
center hole to the proper diameter. Through this hole I inserted a
brass bushing that was originally intended as a through chassis
shaft bushing for a radio set. I faced the washer with a leather
disc cut from the tongue of an old shoe using a smaller washer to
hold it flat against the larger washer. I had a valve that was not
too far from the original and, as it turned out, worked quite well.
I subsequently rebuilt the original valve assembly using a piece of
leather more closely resembling the manufacturers version. I never
did get the rusted nut to thread off, and had to cut it off and
replace it with a new one after I chased the threads with a die of
the proper size. The engine can’t tell the difference between
my homemade valve and the rebuilt original, but I put the original
in for some degree of authenticity. After all I had taken some
liberty with the paint job. I applied about half a roll of teflon
tape to the threads of the mixer just outward of the set screw hole
and achieved a reasonably good air seal when the mixer was aligned
in the proper, verticle position. After the linkage and gas lines
were reconnected and with the first crank the engine actually tried
to start! Oh ecstasy! After some experimentation and tinkering with
the setting of the needle valve and the throttle adjusting screw
and some more cranking, I had the little engine up and running. It
purred like as kitten, responded to the adjustments with spirit.
But there was more noise generated by the crank-case breather cap
and the mixer air valve than by the engine exhaust. I let it run
for about an hour and just stood there watching and listening.

The intake valve made a funny snuffling sound like an old sow
rooting for acorns burried shallow. I concluded that the valve was
vibrating in the guide due to excessive clearance brought on, no
doubt, by the forceful removal with a mallet of the old valve and
clearing rust in the guide. I increased the spring tension but to
no avail. So the head had to come off again and the valve problem
needed to be solved. I miked the valve stem at .308 inches and the
guide at .311. I dug around in my collection of bits and pieces and
turned up an NOS valve for a model A Ford which looked like it
might solve the problem. It could not be tried in the valve guide
until I cut off the flared end. So I cut it to length and dropped
it into the guide. The fit was almost perfect. I had to drill a
hole for the keeper and all was well. I had anticipated the need to
grind the head a little smaller but seating was very nearly perfect
and after slippng it into the seat with a little compound I put the
head back together and re-installed it on the engine. After two
revs with my hand choking the inlet to the mixer the engine started
and purred as before. Most of the valve chatter was gone though it
still showed a tendency to make that chattering sound. The leather
faced air valve makes more noise than the intake valve though and
I’m, leaving it as it is for now. I will probably, one day,
need to drill and shim the guide to get a more perfect fit-one
day.

I put the decals on the water hopper and as can be seen from the
picture, I’ve got a Cushman Cub that is very nearly in
factory-new condition and appearance. I am proud of myself because
I usually have to call on Gabe for help to coax a reluctant
restoration job to get going but this time I was successful all on
my own. But I am proudest of the little engine for the way that it
responded after so many years of neglect.

One consideration that merits recognition here is the fact that
had I continued my restoration efforts without interruption, I
would have had this little Cushman Cub ready for that Memorial Day
show just as Gabe had predicted when he first dragged the pile of
rust into my lab. Gabe is not often wrong in his assessment of old
engines.

In any case, there is no doubt about it, this is one Cub that
has definitely come out of hibernation! Now, just wait for Memorial
Day 1988!

  • Published on Oct 1, 1987
© Copyright 2022. All Rights Reserved - Ogden Publications, Inc.