Shindaiwa HT254EF - Manual (Page 15)

15
135-Hour or Annual Maintenance
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.
Combustion 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.
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).
Valve Adjustment
Remove cylinder cover, rocker arm cover, and set piston at TDC-compression. 1.
Loosen adjuster locknut so that the 2.
2.5 mm Allen socket head adjustment screw can turn freely.
Insert feeler gauge .004 (0.10 mm) for both intake and exhaust; between valve
3.
stem tip and rocker arm.
Turn adjustment screw (clockwise = tighter, counter-clockwise = looser) until
4.
feeler gauge is almost snug. Back off just enough to allow gauge to slip out with
limited resistance.
While holding adjustment screw in place with Allen driver, tighten locknut with wrench.
5.
Turn engine over several times, and return to TDC-compression. Recheck with proper 6.
feeler gauge to make sure clearance adjustment did not change as a result of tighten-
ing locknut. Readjust as necessary.
Replace rocker arm cover gasket to assure proper sealing and install cover.
7.
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 24
Figure 25
Figure 23