IGNITION SYSTEM
Several factors contribute to the overall performance of an ignition system - all components must
be in good condition and the spark must be properly timed.
Hard starting,
low power and erratic opera-
tion can often be attributed to faulty ignition.
If poor ignition is suspected, the first thing to do is to
determine if this system is actually at fault.
A simple operational test will determine this.
OPERATIONAL TEST: Remove the high tension lead at the spark plug,
bend paper clip and insert into
boot then hold the end about l/16” to l/8*! away (with insulated pliers to prevent electrical shock) from
the cylinder head while cranking the engine.
If a sharp snappy spark occurs, the trouble is apparently
not in the magneto although it could still be attributed to a poor spark plug.
If no spark or a very weak
spark occurs,
ignition trouble is indicated.
When checking out an ignition system, the components most
commonly requiring service or adjustment should be checked first.
TO
ENGINE FlRliG ORDER
l-3-4-2
I
ON STANDARD
PLUGS AT .025"
I
FIGURE 5-l
-- HIGH TENSION LEAD CONNECTIONS - STANDARD MAGNETO
SPARK PLUG SERVICE
Engine misfire or generally poor operation is often caused by spark plugs in poor condition or
with improper gap setiing.
Plugs fail for various reasons.
Often the porcelain insulator cracks or
becomes coated with oil, carbon or other deposits which causes the high voltage ignition impulse to
pass from the center electrode to ground without jumping the plug gap. As’an engine operates, the
electrodes are gradually burned or worn away.
In time, the gap becomes so wide that the available
ignition voltage cannot jump the gap and the engine misses.
Spark Plug Service: Every 100 hours, remove plug,
check condition and reset gap. Good operating
conditions are indicated if plugs have a light coating of gray or tan deposit.
A dead white, blistered
coating could indicate overheating.
A black (carbon) coating may indicate an *roverrichJt fuel mixture
caused by clogged air cleaner or improper carburetor adjustment.
Do not sandblast, wire brush, scrape
or otherwise service plug in poor condition -
best results are obtainmh new plug.
Use Champion 58
or equivalent spark plugs with standard ignition and Kohler #24Q705-S with the shielded ignition system.
For gasoline operation, set spark plug gap at .025*‘,
or at .018” on gas fuel and on shielded plugs.
Tighten plugs to 22 ft. tbs. torque.
51
l
To Next Page
Loading...
