AJS Highway Star 125, Owner'S Manual, Page: 52 / 61

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TROUBLESHOOTING
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Possible Cause Remedy
1) Incorrect tappet clearances.
2) Loose spark plug.
3) Worn piston / cylinder.
3) Bent / sticking valve/s.
4) Leaking head gasket.
5) Burnt piston.
1) Loose exhaust.
2) Incorrect tappet clearances.
3) Damaged valve gear.
4) Excessive piston to cylinder
clearance.
5) Crankshaft bearings worn.
6) Clutch worn.
7) Worn balance shaft bearings/gears.
8) Magneto flywheel loose.
1) Adjust the tappets to 0.15mm clearance.
each. Inlet and Exhaust.
2) Tighten the spark plug.
3) Replace the valves.
4) Replace the head gasket.
5) Replace the piston. Check fuel/air
mixture.
1) Tighten the exhaust fasteners.
2) Adjust the tappets to 0.15mm clearance each.
Inlet and Exhaust.
3) Check / repair valve gear.
4) Replace cylinder, piston and gaskets.
5) Replace clutch.
6) Replace the balance shaft.
7) Tighten the flywheel. Check for damage to
crankshaft and flywheel.