Generac Power Systems MC - Manual (Page 77)

CTLINCW
PISTON
,pi3TON R ing
Check ring gaps on worn rings to
determine if rings should be re­
placed. Check gaps on new rings
to determine if cylinder should
be rebored. To check ring gap,
square the ring in the cylinder
bore as shown above.
After squaring the ring in bore,
use feeler gauge to check ring
gap.
3.3.2J-VALVES
Intake.and exhaust valves are NOT
identical - intake valves are id­
entified by the letter ”1”, exhaust
valves by an "E**.
Clean valve parts in iion-Clainmahle solvent. Remove carbon from valves.
Replace distorted or damaged valves. If valves are useable, they may
be ground to a 45 degree angle. When new or re-ground valves are to be
installed, lap them to ensue a gas tight fit. Lap valves as follows
1. Coat valve face sparingly with a fine grade of valve grinding comp­
ound.
2. Rotate valve on valve seat. Lift valve from seat every 8 - 1 0
strokes to keep compound equalized on surface of valve seat.
3. Continue lapping until both the valve and seat has a smooth surf­
ace. Clean thoroughly to remove all traces of lapping compound.
Dry thoroughly.
To obtain correct valve tappet clearance, grind ends of valve stems
off squarely. Use a V-block to hold valve stem square to grinding
wheel. After grinding, check for proper clearance as follows
3 . 3 - 7