1
. GENERAL INFORMATION
TROUBLESHOOTING
ENGINE WILL NOT START OR IS HARD TO START
Inspection/Adjustment
Check if fuel reaches
carburetor by loosening
drain screw.
Remove spark plug and
install it into spark plug
cap to test spark by
connecting it to engine
ground.
Test cylinder
compression.
Start engine by follow-
ing normal starting
procedure.
Remove spark plug and
inspect again.
Wait for 30 minutes and
then remove the carbu-
retor auto choke circuit
hose and blow the hose
with mouth.
Symptom
Fuel reaches
Fuel does not
carburetor
reach carburetor
Weak or no spark
Spark jumps
Normal
compression
Engine does not
Engine fires but
fire
does not start
Wet spark plug
Dry spark plug
Not clogged
Probable Cause
Empty fuel tank
Clogged float valve
Clogged charcoal canister
Clogged fuel filter
Faulty auto fuel valve
Faulty spark plug
Fouled spark plug
Faulty CDI unit
Faulty A.C. generator
Broken or shorted ignition coil
Broken or shorted exciter coil
Faulty ignition switch
Burned or worn cylinder
piston
Low or no
Faulty reed valve
compression
Blown cylinder head gasket
Leaking crankcase
Faulty crankcase oil seal
Incorrectly adjusted idle speed
Air leaking through intake
pipe
Incorrect ignition timing
Flooded carburetor
Throttle valve excessively
open
Clogged
Faulty auto bystarter
ATV 50
1-30