Rocker Arm Stud Kit; Valve Adjustment; Hydraulic Roller Valve Lifters - Mercury MerCruiser MCM 454 Mag MPI Service Manual

SERVICE MANUAL NUMBER 23

Rocker Arm Stud Kit

These engines use a net lash or non-adjustable rocker arm system. Torquing the rocker arm
bolt to 40 lb-ft (54 Nm) sets the valve lash. When rebuilding these engines with a net lash,
machining of the cylinder deck surface or cylinder head surface or grinding the valve seats
or valves may cause an incorrect valve lash condition. The most common problem is that
the valves will not close completely after the bolt is torqued.
The kit can be used to convert the engine from a non-adjustable to an adjustable valve lash
engine. There are 8 studs and 8 nuts in each kit. The valve lash is 1 turn down from "0" lash.

Valve Adjustment

No adjustment is required. Valve lash is automatically set when rocker arm bolts are torqued
to 40 lb-ft (54 Nm).

Hydraulic Roller Valve Lifters

Hydraulic valve lifters require little attention. Lifters are extremely simple in design.
Normally, readjustments are not necessary and servicing requires only that care and
cleanliness be exercised in the handling of parts.
Index
90-861326--1 MARCH 1999
Downloaded from https://needmanual.com/
Roller Lifter
1 - Push Rod Seat Retainer
2 - Push Rod Seat
3 - Metering Valve
4 - Plunger
5 - Check Ball
6 - Check Ball Spring
7 - Check Ball Retainer
8 - Plunger Spring
9 - Lifter Body
1
2
3
4
5
6
7
454 CID (7.4L) / 502 CID (8.2L)
8
9
72031
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