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Governor fails to work. Engine
races, cuts out too soon, or stops.
No compression. Runs first fast,
then slow. Suddenly speeds up or
slows down. Picks up badly under

Clean thoroughly and oil well.
Look after springs and see that
all parts move readily and freely
but are not loose.


Ignition bad. Engine runs slug-
gishly and unevenly. Sometimes
runs jerkily. Will start on prim-
ing charge but not run itself. Mis-
fires. Back explosions. Muffler
explosions. Pound.

piece in gear case. Broken ball in
thrust bearing. Gear out of line
with engine.

Springs too strong or too weak
or broken. Arms of weights stuck
or bent. Toggles, or sliding collar,
stuck or jammed. Loose parts
causing backlash. Mechanism out
of true

badly adjusted.
Springs rusty or parts gummed
from old oil or paint.

Short circuits; weak batteries.
Coil burnt out or vibrator stuck.
Short circuit in coil of timer. En-
gine timed so that ignition takes
place too late or too early. Timer
contacts worn.

Wires broken or
insulation bad. Magneto broken,
short-circuited, belt slips.
Brushes worn or dirty. Oil or
water on spark-plug points. Ig-
niter points worn or dirty. Mica
packing broken or oil-filled. Ig-
niter springs too weak or rocker

Overhaul wires and test bat-
teries and coil. Clean vibrator.
Try a new coil. Clean contacts
and all connections on switch, coil,
and plug. Clean plug or use new
one. Clean timer and oil it well.
Try on batteries without magneto.
Replace brushes if worn. Try new
springs on igniter. Clean spindle
with kerosene. Tighten rocker on
spindle. Clean mica packing or
replace. If wires are wet or oil-
soaked try new wire. Remember


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that most motor troubles are in
the ignition.

Retard spark. Clean plug and
cylinder. Look at rings. Test all
parts for looseness. Watch timer
for sparks in same. Test for short
circuits. Thoroughly oil all parts.
Examine for water.

Try with
muffler disconnected. Give richer

spindle stuck, bent, or rocker
loose on spindle.

Pre-ignition. Spark too far ad-
vanced. Soot or carbon in cylin-
der or plug. Short circuit in timer.
Overheated engine. Want of oil.
Poor oil. Some part loose, cracked,
or broken. Worn or dry bearings.
Loose piston pin. Broken rings.
Loose weights on

governor or
parts of governor striking en-
gine. Choked muffler or too small
exhaust pipe. Water in cylinder
or base. Too weak a mixture.

Faulty ignition. Poor mixture.
Faulty lubrication. Too much air
in mixture causes base explosions.
Too much gasolene causes misfires
and black smoke. Too much oil
causes blue smoke. Failure to
turn over more than once or twice
when started shows too rich mix-
ture or some stoppage in gasolene
supply, inlet valve stuck, or base

Loss of power, or poor speed.
Sluggish running. Misfires. Back
explosions. Smoke from base of
engine and carburetor. Black
smoke from exhaust. Blue smoke
from exhaust. Failure to run even
when motor starts easily.

Overhaul ignition. Give more
or less fuel as required. Give
more or less oil. Drain and clean
carburetor, pipes, and tank. Try
new spring in check valve. Work
the inlet valve by hand and clean
with kerosene. Use a heavier
grade of oil on bearings.

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compression leaky in two-cycle
engines. Also caused by failure
of check valve to seat properly in
two-port engines.

Poor cil or oil of an improper Try a different grade of oil and
consistency. Forgetting to oil or thoroughly, clean all oilers, pipes
failure to feed oil regularly. Oil and feeds, and oil connections.
feeds choked with old oil, dirt, or Adjust feeds accurately to feed
water. Oil-pump (in force feed) more or less as required. Try new
out of order; belt or friction drive belt or friction wheel. Test tank
to oiler slips. Particles of grit or for leakage. Use the best oil
metal in oil. Leak in oiler tank. money can buy; oil is cheaper

than engines.
Ignition or carburetor troubles. Overhaul ignition as for troubles
Dirty plugs, connections, already described. Try
switch contacts. If engine runs switch, wires, or timer. Keep
slower and slower and then stops timer well oiled. Use new bat-
without overheating, batteries are teries. See that belt, gear, or fric-
run down. Timer dry, dirty, or tion on magneto drive are not

Igniter binds in bushing slipping. Try without muffler or
when hot. Muffler chokes up or with cut-out open. Depress float
carburetor does not feed as fast as on carburetor. Give more gaso-
motor requires. Tank too low or lene or less as required. Raise



Misfires. Engine runs slug-
gishly or jerkily. Runs well a
short time and then slows down
and stops. Explosions in base or



Muffler troubles. Loud explo-
sions, noises, rattle. Hissing.

no air-vent. Dirt or water in
pipes. Float set too low. Needle
valve or throttle shakes shut.

Unexploded gas entering muffler
and exploding by heat of same or
by burning gas from next exhaust-
ed charge. Muffler choked or too
rich a mixture used. Misfires.
Poor ignition or leaky valves.

Noises and rattle around engine.

Loose nuts or bolts. Loose' con-
nections. Worn valves or push
rods. Poor springs or loose small
parts. Some part bent, cracked,
or out of adjustment. Common
trouble make - and - break

tank. See that air-vent is free.
Tighten lock nuts on valve or

Slow motor down before stop-
ping. Shut off by throttle before
using switch. Use water-cooled
exhaust or muffler. Clean muffler.
Tighten up all muffler and exhaust
connections and bolts. Use weak-
er mixture.

Tighten up all connections,
screws, and nuts. Hold piece of
wood, or hand, on various parts
to determine where noise origi-
nates. Oil well. Place fibre wash-
ers under springs and wherever
two pieces of metal hit or rattle
against one another. Replace
these washers as fast as worn out.
Take up all lost motion.

Renew or clean all pipes, radi-
ator, etc.

Examine pump and
pump-drive. Examine check
valves and clean. Tighten or re-


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place packing. Tighten all joints
on intake water-pipe. Force water
or air back through outboard inlet
on marine motors. Flush water-
jacket by forcing water back
through it. Use an exhaust valve
with longer stem. Adjust mixture
and oil feeds. Stop engine at once
and allow to cool gradually. Do
not throw cold water on it. Oil
well and turn over by hand several
times before attempting to start it
again. Never run a motor when
it overheats.

Pour kerosene through head of
cylinder and turn engine over a
number of times. Oil well and
drain all kerosene from base.
Examine rings and piston. Clean
grooves and replace rings or use

If cylinder is scored
replace or have rebored. Examine
connecting rod, piston pin, and
bearings. Clean out all carbon

Piston troubles. Piston pounds,
seizes, or is too loose. Engine stops
or is very hard to turn over.

Poor lubrication.

Piston rings
stuck in grooves. Bröken or worn
rings. Cylinder scored from using
broken rings. Gummy or poor oil.
Overheating. Grit or rust in cyl-
inder. Connecting rod or piston-
pin bearings worn out of true,
allowing piston to cant to one side
and jam. Connecting rod bent.

new ones.

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