Cylinder Head/Valve Troubleshooting - Honda NSA700A DN-1 2009 Service Manual

TROUBLESHOOTING
• Engine top-end problem s usually affect engine perform ance. These can be diagnosed by a com pression test, o r by trac­
ing top-end noise w ith a sounding rod o r stethoscope.
• If the performance is poor at low speeds, check fo r w h ite smoke in the crankcase breather hose. If the hose is smoky,
check for a seized piston ring (page 10-4).
Compression too low , hard sta rtin g o r p o o r perform ance at lo w speed
• Valves
- Incorrect valve clearance adjustm ent
- Burned or bent valves
- Incorrect valve tim in g
- Broken valve spring
- Uneven valve seating
- Valve stuck open
• Cylinder head
- Leaking or damaged cylinder head gasket
- Warped or cracked cylinder head
- Loose sparkplug
• Cylinder/piston problem (page 10-3)
Compression too high
• Excessive carbon build-up on piston head o r com bustion cham ber
Excessive smoke
• Worn valve stem o r valve guide
• Damaged stem seal
• Cylinder/piston problem (page 10-3)
Excessive noise
• Incorrect valve clearance adjustm ent
• Sticking valve or broken valve spring
• Excessive worn valve seat
• Worn or damaged cam shaft
• Worn or damaged rocker arm and/or shaft
• Worn rocker arm fo llo w e r o r valve stem end
• Worn cam sprocket teeth
• Worn cam chain
• Worn or damaged cam chain tensioner
• Cylinder/piston problem (page 10-3)
Rough idle
• Low cylinder compression
CYLINDER HEAD/VALVE