MTD 94-2105-B - Manual (Page 19)

Clean Engine—Remove dirt and debris with a cloth or
brush. Cleaning with a forceful spray of water is not
recommended as water could contaminate the fuel
system.
A WARNING; Periodically clean muffler area to
remove all dirt and combustible debris.
Clean Cooling System
Yearly or every 100 hours, whichever occurs first,
remove the blower housing and clean the area shown
to avoid overspeeding, overheating and engine
damage. Clean more often if necessary.
Remove Combustion Deposits every 100-300 hours
of operation. Remove cylinder head and cylinder head
shield. Scrape and wire brush the combustion deposits
from cylinder, cylinder head, top of piston and around
valves. Use a soft brush to remove deposits. Re­
assemble gasket, cylinder head and cylinder head
shield. Turn screws down finger tight, with the three
longer screws around the exhaust valve. Torque
cylinder head screws in a staggered sequence to 140
inch pounds (15.82 Nm).
Spark Plug—Clean and reset gap at .030" every 100
hours of operation.
NOTE: Do not blast clean spark plug. Spark plug
should be cleaned by scraping or wire brushing and
washing with .a commercial solvent.
Clean Out
Chaff and Dirt
\
Caution: Sparking can occur if wire terminal does not
fit firmly on spark plug, or if stop switch vibrates against
spark plug. Reform terminal or repair switch if
necessary.
Spark Arrester Equipped Muffler—If engine muffler
is equipped with spark arrester screen assembly,
remove every 50 hours for cleaning and inspection.
Replace if damaged.
SECTION 4
ADJUSTMENTS'
CARBURETOR ADJUSTMENT
A WARNING; If any adjustments are made to
the engine while the engine is running (e.g.
carburetor), keep clear of alt moving parts. Be
careful of heated surfaces and muffler.
Minor carburetor adjustment may be required to com­
pensate for differences in fuel, temperature, altitude or
load.
NOTE: The air cleaner must be assembled to car­
buretor when running engine.
To Adjust Carburetor—Gently turn idle mixture valve
clockwise until it just closes. Valve may be damaged
by turning it in too far.
Next, open the valve 1 turns counterclockwise. This
initial adjustment will permit the engine to be started
and warmed up (approximately 5 minutes) prior to final
adjustment.
Final Adjustment—Place throttle control lever in
SLOW position. Then rotate throttle counterclockwise
and hold against throttle stop while adjusting idle RPM
by turning idle speed adjusting screw to obtain 1750
RPM. Turn idle mixture valve in (clockwise—lean mix­
ture) until engine just starts to slow. Then turn idle mix­
ture valve out (counterclockwise—rich mixture) until
engine runs unevenly. Now turn idle mixture valve mid­
way between rich and lean. Release throttle—engine
snould accelerate smoothly. If engine does not ac­
celerate properly, the carburetor should be readjusted,
usually to a slightly richer mixture by turning idle mix­
ture valve counterclockwise 1/8 turn more.
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