Yanmar 2YM15 - Camshaft and Tappets; Camshaft

5. Inspection and servicing of basic engine parts
128R1
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.
(2) Measure the cam height, and replace the
cam if it is worn beyond the limit.
mm
Standard Limit
Camshaft side gap 0.05-0.15 0.25
3YM30 mm
Standard Limit
Cam height
Intake
34.135-34.265 33.89
Exhaust
3YM20/2YM15 mm
Standard Limit
Cam height
Intake
34.535-34.665 34.29
Exhaust
Push rod
Tappet
Camshaft gear
Thrust metal
Camshaft bushing
Camshaft
(Camshaft side gap)
Camshaft gear
Thrust metal
Side gap
(Cam height)
Cam height
Micrometer