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LITTLE HOUSE PROJECT
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PLAIN
CLUES TO MOTOR ILLS
by Martin Bunn
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Many Things
You Can Learn
About an Engine by Using
Your Eyes and Ears.
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Young Henry
Canton jabbed his toe viciously at the starter button. A feeble whir was
the only response.
"It's no use,
Hank," insisted Gus Wilson who was standing with one foot poised on the
running board. "Your battery's deader than a door nail. Calm down and
we'll take a look."
"But it's brand new,"
Canton
protested as the gray-haired mechanic lifted the seat and unlimbered the
bolts that held the battery box cover in place. "Say, if that batter's dead
already, I've been gypped. I'll go to that fellow that said it to me and -
"
"Hold your
horses," broke in Gus. "No sense getting excited. Let's find out a few
things first."
The veteran
garage man switched the headlights on and off several times. Then he asked
casually, "Who put the battery in for you?"
"I did, of course,"
Canton
replied proudly. "And I tightened the cables tighter than a drum."
Gus merely
shrugged his shoulders as he switched the headlights on again. "Maybe so,
but take a squint at that, Hank," he said, jerking his horny thumb in the
direction of the dashboard as the tiny ammeter needle swung from its off
position to the charge side of the dial.
Canton
craned his neck.
"It takes a
better battery than any I've seen to register 'charge' when the lights are
on and you're standing still," Gus added grinning. "You tightened the cable
clamps all right, but you tightened them on the wrong terminals. Don't you
know a battery has a plan and a minus?"
Canton
scratched his head as a flush mounted to his cheeks. "Gosh, that's right,
too," he mumbled sheepishly.
"You just
drained all the pep out of your battery," said Gus. "With the battery and
generator connected up wrong, they bucked each other every time you ran the
car. The battery couldn't store up any current, but a good charging will
fix that up."
"How about the generator?" put in
Canton,
"Was that hurt?"
"May have
burned the cut-out points a bit, but I can fix them in a jiffy," Gus told
him.
A half hour
later, Gus had installed a rental battery, and announced that the car was as
good as new.
"Well, that's one on me," said
Canton.
"If I had looked at that ammeter, everything would have been O. K."
"Sure, but
you could stumble over a gold brick if you didn't know what to look for,"
Gus reminded him.
"Here, I'll
show you what I mean."
Gus led the
way across the garage driveway to a small pile of old tires.
"What would
you say about this?" he asked as he selected one and pointed to a large worn
spot on the otherwise solid tread.
"Looks like it was weak to begin with. Probably something wrong with the
rubber,"
Canton
guessed.
Gus grinned.
"That's just what the owner of the tire claimed. He sworn up and down that
I knew it was a bum shoe when I sold it.
"But, any time
you see a tire that's got a single worn spot like that," he went on. "you
can blame it on the brake on that particular wheel. Either the drum's out
of round or there's something wrong that makes the wheel stop in the same
spot every time you jam on the brakes. Naturally the tire's going to wear.
As far as stopping goes, it's only using about one-fiftieth of its tread.
"And
that's not the only clue your tires can give you," Gus continued as they
strolled back to
Canton's
car. "Take the front tires. If the outer edges are rounded and the inner
edges are worn so they're jagged or fringed, it's a sign the wheels toe in
too much.
"On the other
hand, if only one of the tires in front shows this kind of wear, it's not
the toe-in but a sprung axle or steering knuckle. Then again, if they both
wear, but one wears faster than the other, it's probably the camber."
"That reminds me," said
Canton
when Gus had finished.
"A friend of
mine has a front tire that looks like it's been through a siege of
smallpox. Big pieces are gouged out of the tread all the way around. Does
that mean anything besides hard use or running over sharp rocks?"
"You bet it
does," declared Gus. "Either a wheel bearing is worn or else something's
loose in the steering gear. Either trouble would make the wheel wobble and
grind itself to pieces on the pavement.
"Then take
your lights," Gus continued. "They're another good source of clues.
Between your lights and your ammeter, you ought to be able to find out
anything you want to know about your ignition system.
"Flickering
lights, for example, are a pretty good indication that there's a short some
place in the lighting circuit. To find it, all you've got to do is turn on
your headlights, then your side lights, and finally the dash and dome
lights. If the lights flicker in all three cases, you've traced the short
to the tail light. If they only flicker when the headlights are on, look in
the headlight circuit. The same thing holds true for the side lights and
inside lights.
"If the
lights flicker every time you switch on the ignition, look in the ignition
circuit. Lights that flare up when you speed up the motor mean that there's
a loose connection somewhere in the battery and generator circuit."
"Is there anything in all this stuff about smoky exhausts meaning trouble?"
Canton
asked.
"In a way,
yes," agreed Gus. "Of course, you're going to have a certain amount of
exhaust smoke when the motor is cold, but when it starts to puff out in
clouds, watch out.
"If it's
white or light blue, you've probably got too much oil in the crankcase or
else the oil you're using is too thin. A black smoke that's smelly means
the carburetor's set for too rich a mixture and a gray smoke shows a
combination of both troubles.
"But the
exhaust isn't the only place where smoke will give a tip about the condition
of your engine," Gus continued. "The blue vapor that sometimes puffs out of
the crankcase breather pipe will tell you a heap about your piston rings and
cylinders."
"What's the breather got to do with the piston rings?" asked
Canton,
puzzled.
"Just this,"
Gus pointed out. "If your rings or cylinder walls are worn, some oil is
bound to work past them into the cylinders, where it'll burn and be blown
back into the crankcase. Naturally if it gets into the crankcase, it's
going to leak out through the breather. If it just sort of floats out, it
probably doesn't mean much but when it comes out in puffs you can be pretty
sure one of the pistons is leaking."
"Gosh, you're a regular Sherlock Holmes when it comes to detecting the
faults in cars."
Canton
exclaimed admiringly as he touched the starter button.
"Well, you
need to be to run a garage," Gus told him, "you've got to use your eyes and
your ears as well as your hands to get along. No sense getting all messed
up with grease and oil when you can find out things lots easier by looking
and listening."
END
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