LEHR 15 HP 4-STROKE - Manual (Page 18)

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MAINTENANCE
Spark plug Boots
INSPECTION CHECKPOINTS
Periodically check the fuel system for leaks. With the propane tank attached, and the engine cover removed,
inspect the following fuel system parts for leakage. Leaks can be identified by smell of propane or carefully
listening for a hissing sound of escaping gas. Suspected leaks can be verified by applying soapy water
solution on the area and observing bubbles forming.
The spark plug is an important engine part and is easy to inspect. The condition of the spark plug can
indicate the condition of the engine. Normally, the spark plug in a propane engine will stay very clean.
Oily or dark color ceramic could indicate a malfunction. Do not attempt to diagnose any problems yourself.
Instead, take the outboard motor to a LEHR dealer. You should periodically remove and inspect the spark
plug because the electric arcing will cause the spark plug to slowly erode and the gap will increase.
If electrode erosion becomes excessive, or if carbon and other deposits are excessive, you should replace
the spark plug with another of the correct type.
GREASING
NOTE: Use only water resistant grease.
Spark plug gap:
0.020-0.024 in (0.5-0.6 mm)
Spark plug torque:
13.3 ft-lb (18.0 Nm)
SPARK PLUGS
WARNING: When removing or installing a spark plug, be careful not to damage the insulator. A damaged
insulator could allow external sparks, which could lead to explosion or fire.
Before fitting the spark plug, measure the electrode gap with a wire thickness gauge. Adjust the gap to
specification if necessary.
When fitting the plug, always clean the gasket surface and use a new gasket. Wipe off any dirt from the
threads and screw in the spark plug to the correct torque.
NOTE: If a torque-wrench is not available when you are fitting a spark plug, a good estimate of the correct
torque is 1/4 to 1/2 a turn past finger tight. Have the spark plug adjusted to the correct torque as
soon as possible with a torque wrench.
Spark plug ID mark (i.e. NGK)
Standard spark plug: DPR6EA-9
Grease in these areas: