Camshaft And Tappets; Camshaft - Yanmar 3YM30 Service Manual

5.6 Camshaft and tappets

5.6.1 Camshaft

The camshaft is normalized and the cam and bearing
surfaces are surface hardened and ground. The cams
have a curve that minimized the repeated shocks on the
valve seats and maximizes valve seat life.
(1) Checking the camshaft side gap
Measure the thrust gap before disassembly. As the cam
gear is shrink-fitted to the cam, be careful when
replacing the thrust bearing.
Camshaft side gap
(2) Measure the cam height, and replace the
cam if it is worn beyond the limit.
3YM30
Intake
Cam height
Exhaust
3YM20/2YM15
Intake
Cam height
Exhaust
Standard Limit
0.05-0.15 0.25
Standard Limit
34.135-34.265 33.89
Standard Limit
34.535-34.665 34.29
5. Inspection and servicing of basic engine parts
mm
(Camshaft side gap)
Cam height
mm
mm
128R1
Push rod
Tappet
Camshaft
Camshaft bushing
Camshaft gear
Thrust metal
Camshaft gear
Thrust metal
Side gap
Micrometer
(Cam height)