HER CHEE ATV-320 S Service Manual page 18

Chapter 1 Engine, Transmission & Gear
Troubleshooting
Engine top problems usually affect engine performance. These can be diagnosed by a
compression test, or by tracing noises with a sounding rod or stethoscope.
Low Compression
◦ Valves
— Incorrect valve adjustment
— Burned or bent valves
— Incorrect valve timing
— Broken valve spring
◦ Cylinder head
— Leaking or damaged head gasket
— Warped or cracked cylinder head
◦ Cylinder and piston
Compression Too High
◦ Excessive carbon build-up on piston or combustion chamber
Excessive Noise
◦ Incorrect valve adjustment
◦ Sticking valve or broken valve spring
◦ Damaged or worn camshaft
◦ Loose or worn cam chain
◦ Worn or damaged cam chain tensioner
◦ Worn cam sprocket teeth
◦ Worn rocker arm and/or shaft
I-9