Echo CS-420ES Service Manual

49
ENGINE
CS-370ES
CS-420ES
7-10 Installing piston and piston ring
1. Lubricate needle bearing with 2-stroke engine oil.
2. Set needle bearing and piston pin spacers (A) on
small end of connecting rod (B) as shown.
NOTE: Place piston pin spacers on connecting rod
with dents (a) inside as shown.
NOTE: Place piston over connecting rod with piston
arrow mark (C) pointing as shown.
3. Insert pin guide tool (D) stamped “9”, through
piston, piston pin spacers and needle bearing set
at step 2.
4. Insert piston pin in piston pushing out pin guide
tool until the pin end comes up to snap ring groove
(E).
NOTE: If piston pin is tight, use piston pin tool
897702-30131 with pusher adapter stamped “8”.
5. Install new snap rings on both end of piston pin.
Make sure that they are properly seated in snap ring
grooves.
NOTE: Always use new snap rings.
6. Install piston ring on piston.
D
C
a
A
B
E

Echo CS-420ES Specifications

General

Saw Chain Gauge	0.050 inches
Fuel Capacity	0.41 liters
Weight	4.6 kg
Saw Chain Pitch	3/8 inches
Bar Length	16 inches