Engine Troubleshooting
Problem: Low power output. Engine bogs down or dies under load. Excess exhaust or unburned fuel in exhaust. See chart below:
Engine System | Possible Cause | Possible Solution | ||
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Ignition System | Incorrect Ignition Timing. | Adjust Engine Advance Angle. | ||
Fuel Supply System | 1. | Air in fuel line or fuel line clogged. | 1. | Purge air or clear obstruction. |
| 2. | Main Jet not adjusted properly. | 2. | Readjust Main Jet. |
| 3. | Metering Jet or Main Jet clogged. | 3. | Clean and Readjust. |
| 4. | Fuel Cock clogged. | 4. | Clean or replace as needed. |
| 5. | Carbon Fouling in Combustion | 5. | Clean out Combustion Chamber. |
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| Chamber. |
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| 6. | Clogged Air Filter. | 6. | Clean or replace Air Filter. |
| 7. | Intake Manifold leaking. | 7. | Repair or replace as needed. |
Poor Compression | 1. Worn Piston, Piston Ring or | 1. | Check compression and wear | |
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| Cylinder Wall. |
| tolerances, repair or replace as |
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| needed. |
| 2. | Leaking Cylinder Head Gasket. | 2. | Check compression, replace as |
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| needed. |
| 3. | Worn Valves, Valve Seats, Stems | 3. | Check wear tolerances, repair or |
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| or Valve Guides. |
| replace as needed. |
Problem: Engine does not start or does not run smoothly. See chart below:
Symptom |
| Possible Cause | Possible Solution |
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Engine is Pinging | Excess wear of: | Check wear, replace as needed. | ||||
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| • Piston, Cylinder Wall or Rings. |
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| • Piston Pin or Piston Pin Hole. |
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| • Connecting Rod Wrist Pin. |
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| • | Crankshaft Roller Bearing. |
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Abnormal Com- | 1. | Combustion chamber carbon | 1. | Clean out Combustion chamber and | ||
bustion or engine |
| fouling. |
| spark plug. |
| |
running hot or |
| 2. | Dirty or old gasoline or oil in gas. | 2. | Drain gas, clean out fuel filter and | |
excess smoking. |
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| replace with fresh gas, minimum 91 | ||
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| octane premium unleaded gasoline. | |||
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Engine does not | 1. | Engine Switch in OFF position. | 1. | Move Switch to ON position. | ||
start. |
| 2. | Water in Carburetor Bowl. | 2. | Drain carburetor Bowl, clean Fuel | |
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| Filter. |
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| 3. | Spark Plug gap not correct. | 3. | Clean and | |
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| Replace plug if needed. |
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| 4. | Incorrect Ignition Timing. | 4. | Check timing and adjust. |
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| 5. | Damaged coil or ignition wires. | 5. | Check for damaged wires, test output. | |
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| 6. | Low Oil level. | 6. | Check oil level, top off as needed. | |
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| REV 08g |
Page 18 | For technical questions, please call | SKU 98706 | ||||