Spark Plugs
Spark plugs should be replaced at the recommended intervals
described in the maintenance Schedule. Use only the recommended
spark plug or an equivalent as described in the General Specifications.
Spark plug gap, should be adjusted as recommended in the general
specifications.
When removing spark plugs, always note which cylinder each plug
came out of. Look at the porcelain around the center electrode of
each plug. You can detect many engine problems from the color
and type of deposits that have built up on the white porcelain.
For example, if the deposits are a glossy brown, that cylinder is
burning excess oil. If the deposits are a very dark gray or sooty
black color, your engine is running rich, and you are burning excess
fuel. The optimum color of the deposits on the porcelain is light
tan or light brown. This shows optimum fuel mixture and proper
engine running conditions. If the deposits are almost white, the
engine may be running excessively lean. Lean running is very
detrimental to your engine life, and should be corrected immediately.
If one or more cylinders are burning oil, the smoke from the engine
will be a blue-gray color. Most common causes are piston rings
(worn out or not broken in) and valve stem seals (cut, nicked, or
worn out). If the engine is running rich the exhaust smoke will be
a sooty black color and it will smell like gasoline (on gasoline
engines).
. ENGINE STORAGE
.1 One to Six Months
If the engine or machine is to be placed in storage for a period of
one to six months it is recommended that the following steps ve
followed:
Protect the air cleaner inlet from water entry
Protect the exhaust outlet or muffler outlet from water entry
Check the coolant protection and top off radiator
Store indoors if possible
.2 For Extended Periods
Follow the above recommended procedures, plus do the following:
Drain the engine crankcase and refill with recommended oil
Change the oil filter
Disconnect and remove the battery
Clean exterior surface of the engine
.3 Removing the Engine From Extended Storage
When removing the engine from extended storage:
Install a fully charged battery
Remove all protective coverings from the air inlet, air cleaner,
exhaust and muffler openings
Check the coolant level in the radiator and verify the protection
level
Start the engine and allow it to run at slow idle. Verify engine oil
pressure
Run the engine at idle until the coolant temperature approaches
120 degrees F (49 degrees C)
Run the engine a various speeds for approximately 15 minutes
Shut the engine down, drain the oil, change the oil, filter and re-
fill with the recommended of oil.
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