QuestionI took my yamaha wolverine up ice fishing last weekend. There was a lot of standing water on the lake and we beat up on the ATV pretty good. It was sub freezing every night and on the third day I was riding it and it all of a sudden wouldn't accelerate properly. It would bog down in every gear when I tried to give it too much gas. It ran at low speeds but wouldn't do anything but bog down at faster speeds. I put some stabil in the gas tank thinking there might be water in it but that didn't help. Any suggestions would be greatly appreciated. Thanks for your time.
Patrick
AnswerHi Patrick,
I suspect a main jet obstruction or an intake air restriction.
ATV resource: "www.atvfrontier.com"
Instead of using Sta-Bil, try a product named "Sea Foam." Good stuff!
If you stay with Sta-Bil, be certain to follow label directions carefully. It's important to add correct amount of Sta-Bil; too little-doesn't work, too much-carb needs cleaned.
Hope the fishing was peaceful and plentiful.
Respectfully,
Mark Shively
Dayton, Ohio
The following troubleshooting possible causes cover a variety of motorcycles and ATV's. Some may not apply to your ATV.
Poor Running or No Power at High Speed:
Firing incorrect:
Spark plug dirty, broken, or maladjusted
Spark plug cap shorted or not in good contact
Spark plug incorrect
IC ignitor trouble
Pickup coil trouble
Ignition coil trouble
Fuel/air mixture incorrect:
Starter plunger stuck open
Main jet clogged or wrong size
Jet needle or needle jet worn
Air jet clogged
Fuel level in carburetor float chamber too high or too low
Bleed holes of air bleed pipe or needle jet clogged
Air cleaner clogged, poorly sealed, or missing
Surge tank duct poorly sealed
Water or foreign matter in fuel
Carburetor holder loose
Fuel tank air vent obstructed
Fuel tap clogged
Fuel line clogged
Compression low:
Spark plug loose
Cylinder head not sufficiently tightened down
Cylinder, piston worn
Piston ring bad (worn, weak, broken, or sticking)
Piston ring/land clearance excessive
Cylinder head gasket damaged
Cylinder head warped
Engine not sufficiently warmed up after lash adjuster installation
Valve spring broken or weak
Valve not seating properly (valve bent, worn, or carbon accumulation on the seating surface)
Hydraulic lash adjuster damaged (worn, seizure, or spring broken)
Hydraulic lash adjuster oil passage clogged
Knocking:
Carbon built up in combustion chamber
Fuel poor quality or incorrect
Spark plug incorrect
Coasting enricher trouble
Miscellaneous:
Throttle valve won't fully open
Carburetor vacuum piston doesn't slide smoothly
Brake Dragging
Clutch slipping
Overheating
Engine oil level too high
Engine oil viscosity too high
Drive train trouble
Final gear case oil viscosity too high
Air suction valve trouble
Vacuum switch valve trouble
Balancer mechanism malfunctioning
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Poor Running at Low Speed:
Spark weak:
Battery voltage low
Spark plug dirty, broken, or maladjusted
Spark plug cap or high tension wiring trouble
Spark plug cap shorted or not in good contact
Spark plug incorrect
igniter trouble
Pickup coil trouble
Ignition coil trouble
Fuel/air mixture incorrect:
Pilot screw maladjusted
Pilot jet, or air passage clogged
Air bleed pipe, bleed holes clogged
Pilot passage clogged
Air cleaner clogged, poorly sealed or missing
Starter plunger stuck open
Fuel level in carburetor float chamber too high or too low
Fuel tank air vent obstructed
Carburetor holder loose
Surge tank duct loose
Compression low:
Spark plug loose
Cylinder head not sufficiently tightened down
Cylinder, piston worn
Piston ring bad (worn, weak, broken, or sticking)
Piston ring/land clearance excessive
Cylinder head gasket damaged
Cylinder head warped
Engine not sufficiently warmed up after lash adjuster installation
Valve spring broken or weak
Valve not seating properly (valve bent, worn, or carbon accumulation on the seating surface)
Hydraulic lash adjuster damaged (worn, seizure, or spring broken)
Hydraulic lash adjuster oil passage clogged
Backfiring when decelerating:
acuum switch valve broken
Air suction valve trouble
Coasting enricher trouble
Other:
Igniter trouble
Carburetors not synchronizing
Carburetor vacuum piston doesn't slide smoothly
Engine oil viscosity too high
Drive train trouble
Final gear case oil viscosity too high
Brake dragging
Air suction valve trouble
Vacuum switch valve trouble
