Shindaiwa AHS2510/EVC manual 139/150-Hour Maintenance, Valve Adjustment, Cutter blade adjustment

Maintenance (continued)

139/150-Hour Maintenance

Maintenance after first 139-hours,	Ŷ Replace the spark plug annually: Use	Ŷ The valve clearance should be adjusted
then every 150-hours thereafter.	only the type recommended in the	annually or every 135 hours. It is
Ŷ Combustion chamber should be decar-	”Specifications” section or an equivalent	highly recommended that this is
bonized, and the valve clearance should	resistor type spark plug of the correct	done by a Shindaiwa-trained service
be adjusted. It is highly recommended	heat range. Set spark plug electrode	technician.
that this is done by a Shindaiwa-trained	gap to 0.6 -0.7 mm.
service technician.

Valve Adjustment

1.Remove cylinder cover, rocker arm cover, and spark plug. Rotate the crankshaft while observing the piston through the spark plug opening. When the piston

is at the top of the compression stroke (TDC), the valves can be adjusted.

CAUTION!

ŶPerforming a valve adjustment incorrectly may cause hard starting and/or can damage the engine.

ŶIf you are unfamiliar with this engine or uncomfortable with this procedure, consult with an autho- rized Shindaiwa servicing dealer.

2.Loosen adjuster locknut so that the

2.5 mm Allen socket head adjustment screw can turn freely.

3.Insert 0.10 mm feeler gauge between valve stem tip and rocker arm.

4.Turn adjustment screw (clockwise = tighter, counter-clockwise = looser) until feeler gauge is almost snug. Back off just enough to allow gauge to slip out with limited resistance.

5.While holding the adjustment screw in place with the Allen driver, tighten the locknut with a wrench.

6.Turn engine over several times, and returnthe to TDC-compression. Recheck with proper feeler gauge to make sure clearance adjustment did not change as a result of tightening the locknut. Readjust as necessary.

7.Replace rocker arm cover gasket to assure proper sealing and install cover.

IMPORTANT!

If a new gasket is not available and/or the old gasket is not damaged, the old gasket may be reused. Never use cracked or dam- aged gaskets!

Cutter blade adjustment

WARNING!

The cutter blades are very sharp! Always wear gloves when work- ing around the cutter assembly.

Cutting performance of your machine depends a great deal on proper cutter blade adjustment. Properly adjusted blades will oscillate freely yet help prevent binding of cut material between blades. Adjust blades as follows:

1.Loosen all blade locknuts at least one full turn.

2.Tighten each blade shoulder bolt firmly, and then loosen the shoulder bolts 1/4 to 1/2 turn.

3.Working from the gearcase end, lock each bolt in place by firmly tightening its locknut while preventing the shoul- der bolt from turning.

When shoulder bolt adjustment is cor- rect, there should be a gap of 0.25–0.50

mmbetween the cutter blades and the flat washers, and the flat washer beneath each bolt head should turn freely.

CAUTION!

Operating the trimmer with worn or improperly adjusted cutters will reduce cutter performance and may also dam- age your machine. Never operate the machine with damaged or worn cutters.

	Locknut
Guide Bar
Cutter
Blades	Washer (should
Shoulder Bolt	turn freely)
Adjusting cutter blades

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