Husqvarna 2010 SMR-450, Workshop Manual, Page: 30 / 420

C.2 Part. N. 8000 H1344 (10-2009)
TROUBLES AND REMEDIES
ENGINE
Trouble Cause Remedy
Engine don’t start or starts Inadequate compression
with difficulty 1. Piston seizure Replace
2. Con-rod small or big end seized Replace
3. Piston rings worn Replace
4. Cylinder worn Replace
5. Low torque cylinder head nuts Tighten
6. Head gasket blowing Replace
7. Spark plug loose Tighten
8. Incorrect valve play Adjust
9. Valve springs weak or seized Replace
10. Valves seized Replace
11. Incorrect decompressor adjustment Adjust
No or weak spark
1. Spark plug faulty Replace
2. Spark plug dirty or wet Clean or dry
3. Spark plug gap too large Adjust
4. Ignition coil faulty Replace
5. H.T. leads damaged or short circuiting Check
6. Electronic device faulty Replace
7. R.H. switch faulty Replace
Fuel not reaching carburettor (TC, TXC)
1. Fuel tank cap breather blocked Clean
2. Fuel cock blocked Clean
3. Fuel feed hose blocked Clean
4. Carburettor fuel filter dirty Clean
5. Worn out float valve or worn out floats Replace
6. Rocker blocking float valve Free
Carburettor flooding (TC, TXC)
1. High fuel level in float bowls Adjust
2. Worn out float valve or worn out floats in open position Replace or free
Engine cuts out easily 1. Spark plug dirty Clean
2. Electronic control unit faulty Replace
3. Carburettor jets blocked Clean
4. Idling low Adjust
Engine noisy Piston noise
1. Excessive play between cylinder liner and piston Replace
2. Piston rings or piston rings seats worn Replace
3. Excessive carbon layers inside the combustion chamber,
or on the piston top Clean
4. Worn rocker arm Replace
5. Excessive valve play Adjust
6. Valve springs weak or seized Replace
7. Cam chain worn Replace
8. Incorrect timing chain adjustment Adjust
Crankshaft noise
1. Main bearings worn Replace
2. High radial and axial play at con-rod big end Replace
3. Crankshaft gear damaged Replace
4. Crankshaft nut loose Tighten