Harbor Freight Tools 94187 Automobile Parts User Manual


 
Page 10
SKU 94187 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. Troubleshoot overheating
(see page 11).
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.