Shindaiwa HT254EF, X7502864200 manual Houror Annual Maintenance, Valve Adjustment

135-Hour or Annual Maintenance

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

■■Replace the spark plug annually: Use only NGK CMR5H or equivalent resistor type spark plug of the correct heat range. Set spark plug electrode gap to 0.6 mm (0.024 in).

NOTE:

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

CAUTION!

■■Performing a valve adjustment incorrectly may cause hard starting and/or can damage the unit. Refer to the Service Manual for complete valve adjustment procedure and torque specifications.

■■If you are unfamiliar with this engine or uncomfortable with this procedure, Consult with an authorized Shindaiwa servic- ing dealer.

Valve Adjustment

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

2.Loosen adjuster locknut so that the

2.5 mm Allen socket head adjustment screw can turn freely.

3.Insert feeler gauge .004 (0.10 mm) 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 tighten- ing locknut. Readjust as necessary.

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

IMPORTANT!

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

Figure 23

Figure 24

Figure 25

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