Low engine power, Engine not running smoothly – Harbor Freight Tools 96500 User Manual
Page 10
Page 10
SKU 96500
for technical questions, please call 1-800-444-3353.
low engine power
symptom
probable cause
possible remedy
When pressing Throttle
for higher speed, engine
responds slowly; speed is
decreased; or engine stops.
Incorrect Ignition timing.
Re-adjust ignition advance angle.
Fuel supply problem:
1. Fuel line is clogged or has air
2. Main jet not adjusted properly
3. Carburetor needle valve hole
and main jet clogged
4. Gas valve clogged
5. Carbon buildup in combustion
chamber.
6. Air filter is clogged.
7. Intake pipe leaking.
1. Clean line. Bleed line of air.
2. Readjust jet.
3. Clean needle valve hole and
main jet
4. Clean or replace gas valve.
5. Clean combustion chamber.
6. Clean filter elements.
7. Repair or replace.
Low compression:
1. Piston, piston ring, or cylinder
worn.
2. Air leakage from surface where
cylinder block contacts cylinder
head.
3. Valve clearance incorrect.
4. Valve tightness poor.
1. Replace damaged part.
2. Replace cylinder gaskets.
3. Adjust valve.
4. Repair or replace valve.
engine not running smoothly
symptom
probable cause
possible remedy
Engine pinging.
1. Piston, ring, or cylinder worn.
2. Piston pin and pin hole are
worn excessively.
3. Tie rod small head is worn.
4. Main crankshaft roller bearing
worn.
1. Replace worn part.
2. Replace piston and/or pin.
3. Replace tie rod.
4. Replace roller bearing.
Abnormal combustion.
1. Engine too hot.
2. Carbon fouling in combustion
chamber.
3. Wrong gasoline type.
1. See Troubleshooting page 11,
Engine Excessively Hot
2. Clean chamber.
3. Drain gas from system and
replace with correct type.
Spark plug not firing
correctly
1. Water in carburetor float
chamber.
2. Spark plug electrode gap
wrong.
3. Incorrect ignition timing.
4. Ignition coil malfunction.
1. Clean Carburetor.
2. Adjust spark plug gap.
3. Re-adjust.
4. Repair or replace coil.