Tecumseh HH100 Handbook page 64

C. ENGINE MISSES UNDER LOAD
Cause
Spark plug fouled.
Spark plug porcelain cracked.
Improper spark plug gap.
Pitted magneto breaker points.
Magneto breaker arm sluggish.
Faulty condenser.
Improper carburetor adjustment.
Improper valve clearance.
Weak valve spring.
D. ENGINE LACKS POWER
Choke partially closed.
Improper carburetor adjustment.
Magneto improperly timed.
Loss of compression.
Lack of lubrication.
Air cleaner restricted.
Valves leaking.
Valve timing inaccurate.
Carburetor dirty or damaged.
Ignition system malfunction.
E. ENGINE OVERHEATS
Engine improperly timed.
Carburetor improperly adjusted (lean).
Air flow obstructed.
Excessive load on engine.
Carbon in combustion chamber.
Lack of lubrication.
F. ENGINE SURGES OR RUNS UNEVENLY.
Fuel tank cap vent hole clogged.
Governor parts sticking or binding.
Carburetor throttle linkage or throttle shaft
and/or butterfly binding or sticking.
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Remedy
Clean and regap spark plug.
Replace spark plug.
Regap spark plug.
Clean and dress breaker points. Replace badly
pitted breaker points.
Clean and lubricate breaker point rod and arm.
Check for spring tension.
Check condenser on a tester; replace if defective.
Adjust carburetor.
Adjust valve clearance.
Replace valve spring.
Open choke.
Adjust carburetor.
Time engine.
Check compression.
Fill crankcase to the proper level.
Clean or replace air cleaner.
Grind valves.
Check timing marks on camshaft and crankshaft
gear.
Clean, repair carburetor. See Carburetor Chapter 2.
Check and repair system.
Time engine.
Adjust carburetor.
Remove any obstructions from air passages in shrouds.
Check operation of associated equipment.
Reduce excessive load.
Remove cylinder head and clean carbon from head
and piston.
Fill crankcase to proper level.
Open vent hole.
Clean, and if necessary repair governor parts.
Clean, lubricate, or adjust linkage and deburr throttle
shaft or butterfly.