Valves And Seals (Without Removing Head); Valve Spring Assembly Exploded View; Valve Spring Assembly Removal - Mercury MerCruiser Service Manual

1. Do the first step torque on the rear main bearing cap.
Description
Crankshaft (main) bearing cap bolt—preferred method
2. Using a lead hammer, tap the end of the crankshaft to the rear.
3. Using a lead hammer, tap the end of the crankshaft to the front.
4. Do the final step torque on the bearing cap.
Description
Crankshaft (main) bearing cap bolt—preferred method

Valves and Seals (Without Removing Head)

Valve Spring Assembly Exploded View

e
d
c
b
a
51187

Valve Spring Assembly Removal

1. Remove the rocker arm cover.
2. Remove the spark plug of the cylinder being serviced.
3. Remove the rocker arm assembly.
IMPORTANT: Keep air pressure in the cylinder while springs, caps, and valve locks are removed or the valves will fall into
the cylinder.
4. Install a spark plug port adapter in the spark plug hole and apply 138–206 kPa (20–30 psi) of compressed air to hold the
valves in place.
Description
Spark plug port adapter
NOTE: If compressed air is not available, the piston may be brought up to TDC to keep the valves from falling out of the
cylinder head.
90-8M0099748 eng DECEMBER 2015
a - Valve
b - Valve stem oil seal
c - Valve spring
d - Valve spring retainer
e - Valve spring lock
Engine Inspection and Assembly
First torque
Final torque
© 2016 Mercury Marine
Nm lb‑in.
25 – 18.4
Nm lb‑in.
+90°
SPX Part Number
J23590
Page 3B-69
lb‑ft
lb‑ft