ENGINE LACKS POWER. Honda CBR125R

TROUBLESHOOTING

ENGINE LACKS POWER

1. Drive Train Inspection

Raise wheel off the ground and spin it by hand.

Does the wheel spin freely?

NO – • Brake dragging

• Worn or damaged wheel bearings

• Bent axle

YES –

GO TO STEP 2.

2. Tire Pressure Inspection

Check tire pressure.

Are the tire pressures low?

YES – • Faulty tire valve

• Punctured tire

NO –

GO TO STEP 3.

3. Clutch Inspection

Accelerate rapidly, shift from first to second.

Does the engine speed change accordingly when the gearshift pedal is applied?

NO – • Clutch slipping

• Worn clutch discs/plates

• Warped clutch discs/plates

• Weak clutch spring

• Sticking clutch lifter mechanism

• Additive in engine oil

• Incorrect clutch lever adjustment

YES –

GO TO STEP 4.

4. Engine Performance Inspection

Accelerate lightly.

Does the engine speed increase?

NO – • Dirty air cleaner

• Restricted fuel flow

• Clogged exhaust system.

YES –

GO TO STEP 5.

5. Spark Plug Inspection

Remove and inspect spark plug.

Is the spark plug fouled or discolored?

NO – • Plugs not serviced frequently enough

• Incorrect spark plug heat range

• Incorrect spark plug gap

YES –

GO TO STEP 6.

6. Engine Oil Inspection

Check oil level and condition.

Is there correct level and good condition?

NO – • Oil level too high

• Oil level too low

• Contaminated oil

YES –

GO TO STEP 7.

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TROUBLESHOOTING

7. Ignition Timing Inspection

Check ignition timing.

Is the ignition timing correct?

NO – • Faulty ECM

• Faulty CKP sensor

YES –

GO TO STEP 8.

8. Cylinder compression Inspection

Test the cylinder compression.

Is the compression as specified?

NO – • Improper valve clearance

• Valve stuck open

• Worn cylinder and piston rings

• Damaged cylinder head gasket

• Improper valve timing

YES –

GO TO STEP 9.

9. Fuel Pump Inspection

Inspect the fuel flow.

Is the fuel pump unit normal?

NO – Faulty fuel pump unit

YES –

GO TO STEP 10.

10. PGM-FI system Inspection

Check the PGM-FI system.

Is the PGM-FI system normal?

NO – Faulty PGM-FI system

YES –

GO TO STEP 11.

11. Lubrication Inspection

Remove cylinder head cover and inspect lubrication.

Is the valve train lubricated properly?

NO – • Clogged oil passage

• Faulty oil pump

• Oil strainer screen not serviced frequently enough

YES –

GO TO STEP 12.

12. Over Heating Inspection

Check for engine over heating.

Is the engine over heating?

YES – • Excessive carbon build-up in combustion chamber

• Use of poor quality fuel

• Wrong type of fuel.

• Clutch slipping

NO –

GO TO STEP 13.

13. Engine Knocking Inspection

Accelerate or run at high speed.

Is there knocking?

YES – • Worn piston and cylinder

• Wrong type of fuel

• Excessive carbon build-up in combustion chamber

• Ignition timing too advance (Faulty ECM or CKP sensor)

NO – Engine does not knock.

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