Replacing The Spark Plug - Toro 51903 Manuel De L'utilisateur

3. Initial High Speed Mixture and Idle Speed
Mixture Needle Settings: Turn both the high
speed mixture and idle speed mixture needles
out (counterclockwise) until the limiter caps
stop.
POTENTIAL HAZARD
Engine must be running to make some
carburetor adjustments.
When engine is running, cutting head is
rotating and other parts are moving.
WHAT CAN HAPPEN
Contact with rotating cutting head or other
moving parts could cause serious personal
injury or death.
HOW TO AVOID THE HAZARD
Keep hands, feet and clothing away from
cutting head and other moving parts.
Keep all bystanders and pets away from
unit while making carburetor adjustments.
4. Start the engine and let it run for a minute.
5. Release the throttle trigger and let the engine
idle. If the engine stops, turn the idle speed
screw (Figs. 30 and 31) in (clockwise) 1/8 turn
at a time (as required) until the engine idles.
Note: Forcing the limiter caps with a
screwdriver will damage the needle
tips and the seat in the carburetor body.
6. Final Idle Speed Screw and Idle Speed
Mixture Needle Settings: Adjust the idle speed
screw and idle speed mixture needle for
smoothest engine idle.
A. Turn the idle speed mixture needle (Figs. 30
and 31) in (clockwise) until you hear the
fastest idle; then turn the needle out
(counterclockwise) 1/8 turn.
EN–11
B. Squeeze the throttle trigger. If the engine
falters or hesitates as it accelerates, turn the
idle speed mixture needle (Figs. 30 and 31)
out (counterclockwise) 1/16 turn at a time
until the engine accelerates rapidly.
C. If the idle speed changes significantly
because of Steps a and b, readjust the idle
speed screw (refer to Step 2).
7. Final High Speed Mixture Needle
Adjustment:
A. High speed mixture needle adjustment is
not recommended without a precision high
speed tachometer.
B. The factory presets the high speed mixture
needle at 1-1/4 turns out from the closed
position. Your unit should perform well at
this setting. If additional adjustment of the
high speed mixture needle is required,
contact your local authorized service dealer.
Note: If the limiter caps are removed at any
time, your unit will no longer meet the
1995 California emission regulations
and you will void the warranty.
Note: If the carburetor adjustments do not
help the unit to run properly, contact
your authorized service dealer.

Replacing The Spark Plug

Use a Champion RDJ7Y spark plug (or equivalent).
Correct air gap is 0.020 in (0.5 mm). Remove plug
after every 50 hours of operation and check its
condition.
1. Stop the engine and pull the wire off of the spark
plug.
2. Clean around the spark plug and remove it from
the cylinder head.
Note: Replace a cracked, fouled or dirty
spark plug. Do not sand blast, scrape
or clean electrodes because the engine
could be damaged by grit entering the
cylinder.