Shindaiwa 81704 manual 139/150-Hour Maintenance, Spark Arrester Screen Maintenance

139/150-Hour Maintenance

Maintenance after first 139-hours, then every 150-hours thereafter.

nCombustion chamber should be decar- bonized, and the valve clearance should be adjusted. It is highly recommended that this is done by a Shindaiwa-trained service technician.

nReplace the spark plug annually: Use only NGK CMR5H or equivalent resis- tor type spark plug of the correct heat range. Set spark plug electrode gap to 0.024-0.028 inch (0.6 -0.7 mm).

NOTE:

The NGK CMR5H also meets the requirements for electro magnetic compliance (EMC).

Valve Adjustment

1.Remove cylinder cover, rocker arm cover, and set piston at TDC-compresion.

CAUTION!

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

nIf you are unfamiliar with this engine or uncomfortable with this proce- dure, consult with an authorized Shindaiwa servicing dealer.

2.Loosen adjuster locknut so that the 2.5 mm Allen socket head adjustment screw can turn freely.

3.Insert .004" (0.10 mm) feeler gauge for both intake and exhaust 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 adjustment screw in place with Allen driver, tighten locknut with wrench.

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

7.Replace rocker arm cover gasket to as- sure proper sealing and install cover.

IMPORTANT!

If new gasket is not available and/or old gas- ket is not damaged, old gasket may be reused. Never use cracked or damaged gaskets!

Spark Arrester Screen Maintenance

If the engine becomes sluggish and low on power, check and clean the spark arrester screen.

WARNING!

Never operate the unit with a damage or missing muffler or spark arrester! Operating with a missing or damaged spark arrester is a fire hazard and could also damage your hearing.

1.With a 3 mm hex wrench remove the 3 engine cover screws and the engine cover. See Figure 32.

2.With a 4 mm hex wrench remove the 3 muffler bolts and the muffler. See Figure 32.

3.With a small flat bladed screwdriver remove the 2 screws holding the spark arrester screen and cover to the muffler. See Figure 32.

4.Remove the screen and clean it with a stiff bristle brush.

5.Inspect the cylinder exhaust port for any carbon buildup.

IMPORTANT!

If you note excessive carbon buildup, consult with an authorized Shindaiwa servicing dealer.

6.Reassemble the spark arrester, muffler and engine cover in the reverse order of disassembly.

Engine Cover
Screws
		Engine
		Cover
	Muffler	Muffler
	Gasket
		Muffler
		Bolts
		Spark Arrester
		Screen
		Spark Arrester
	Cover	Cover
Figure 32	Screws

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