Troubleshooting - Mantis 7940 Operator And Parts Manual

Troubleshooting

Problem
1. Tines don't turn when throttle
is depressed
2. Engine fails to start
3. Engine hard to start.
4. There is black smoke coming from
exhaust
5. Engine misses.
6. Engine lacks power.
7. Engine overheats.
8. Engine noisy or knocking.
9. Engine stalls under load.
Cause
• Engine is not seated properly on the gear housing.
• O/I switch is in "O" position.
• No fuel in tank
• Fuel strainer clogged
• Fuel line clogged
• Spark plug shorted or fouled
• Spark plug is broken (cracked porcelain or
electrodes broken).
• Ignition lead wire shorted, broken or disconnected from
spark plug.
• Ignition inoperative
• Water in gasoline
• Gasket leaks (carburetor or cylinder base gasket).
• Weak spark at spark plug
• The muffler screen is clogged.
• Dirt in fuel line or carburetor
• Carburetor improperly adjusted
• Spark plug fouled, broken or incorrect
gap setting
• Weak or intermittent spark at spark plug
• Air filter clogged
• Muffler clogged
• Spark Arrestor Clogged
• Poor compression
• Air flow obstructed
• Spark plug in incorrect heat range
• Bearings, piston ring or cylinder walls are worn.
• Engine overheats.
Contact us at www.mantis.com
Remedy
• Re-install engine following the instructions on
page 16 "How to reseat the flange."
• Move switch to "I"
• Fill tank.
• Replace strainer.
• Clean fuel line.
• Install new spark plug.
• Replace spark plug.
• Replace lead wire or attach to spark plug.
• Contact your local authorized dealer.
• Drain entire system and refill with fresh fuel.
• Replace gaskets.
• Contact your local authorized dealer.
• Clean carbon from muffler screen.
See engine manual.
• Remove and clean.
• See "Carburetor Adjustment" in engine manual.
• Clean or replace spark plug - set gap to .024-.028
in. (0.6-0.7 mm).
• Contact your local authorized dealer.
• Clean or replace air filter (page 15).
• Clean carbon from muffler, see engine manual.
• Clean Spark Arrestor; see engine manual.
• Contact your local authorized dealer.
• Clean flywheel cylinder fins and screen.
See engine manual.
• Replace with plugs specified for engine.
• Contact your local authorized dealer.
• Remove dust and dirt from between fins.
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