50
ENGINE
CS-370ES
CS-420ES
7-11 Installing piston into cylinder
1. Apply 2-stroke oil on cylinder walls, oil seal
grooves, piston ring, ball bearing, and both sides of
con-rod.
2. Position end gap of piston ring with locating pin
(A).
3. Install piston in cylinder with arrow (B) pointing to
muffler side.
NOTE: When installing piston in cylinder, do not twist
cylinder to avoid breakage of piston ring and scoring
cylinder bore.
4. Make sure that rims of oil seal are properly seated
in the grooves of cylinder (upper crankcase).
5. Apply liquid gasket (Loctite #515: Parts No.
890610-00051, or equivalent) on seams (C) of lower
crankcase half.
6. Apply adhesive (Loctite #675 or equivalent) on
bearing bores (D) of lower crankcase half as shown.
7. Set crankcase halves as shown. Fasten 4 bolts
(E).
NOTE: When assembling cylinder to lower
crankcase, match them together in correct direction
referring to two threaded holes (F) for auto-oiler
assembly.
C
D
E
F
A
B