User Manual

Page 9-10
200 TROUBLESHOOTING
CAMSHAFT TIMING CHECK
Correct camshaft timing is essential for proper
engine performance. Incorrect camshaft timing
may be suspected if soon after engine overhaul,
lack of performance, unusual noise or excessive
smoke are reported.
Camshaft timing can be checked using either
cylinder No. 3 or No. 4 inlet valve. For example
purposes, No. 3 cylinder will be used in the steps
below.
1. Remove cylinder head cover over cylinder
No. 3.
2. Locate inlet valve(s) for the No. 3 cylinder
(the sixth valve from front of the engine).
Position No. 3 piston at Top Dead Center
(TDC) (compression stroke).
3. Loosen (back off) the inlet valve rocker
adjusting screw. Ensure valve yoke is
correctly adjusted. Adjust inlet valve to zero
lash.
4. Position dial indicator (magnetic-base type)
probe on valve spring retainer. Preload
indicator to 1/2 indicator plunger travel.
5. Bar the engine in direction of normal rotation
and carefully observe direction in which
needle of indicator travels. Use dial indicator
to determine when the inlet valve is fully
open.
6. Stop rotating engine when travel of dial
indicator needle stops. If dial indicator
needle reverses direction, full-open position
is passed. Repeat procedure.
7. Check timing indicator. Pointer should be
within three degrees (retard or advance) of
timing indicator specification given in table
that follows. A difference of approximately
10 degrees indicates crankshaft to camshaft
timing gears may be mismatched one tooth.
8. If the engine has a front timing indicator, the
pointer marked PUMP must be used for the
camshaft timing check. The pointer marked
VALVE is used only for valve adjustment.
CAMSHAFT AND TIMING INDICATOR RELATIONSHIP
CAMSHAFT LOBE LIFT CHECK
When diagnosing potential lifter or camshaft
failures, 0.030 inch (0.76 mm) less than the lift of
a new camshaft is considered the minimum
acceptable camshaft lobe lift for used
components. Intake lobe lift differs depending on
the camshaft part number. Camshaft lobe lift is
measured by using a dial indicator at the push
rod with the rocker arm adjusted to zero lash.
Refer to the chart below for the minimum
acceptable camshaft lobe lift for the different part
number E7 camshafts.
MINIMUM ACCEPTABLE CAMSHAFT LOBE LIFT
Camshaft Part No. Timing Indicator
583, 583A 20 degrees BTDC
5142 26 degrees BTDC
5205 27 degrees BTDC
Camshaft Part
No.
Exhaust Lobe Intake Lobe
454GC583,
454GC583A
0.300" 0.300"
454GC5142 0.300" 0.270"
454GC5205 0.300" 0.280"
5-101.bk Page 10 Friday, March 17, 2006 11:05 AM