Replacement - MerCruiser GM4 Service Manual

Replacement

1. Remove primary and condenser lead wires from
contact point terminal.
2. Remove contact set attaching screw and lift con-
tact point set from breaker plate.
3. Clean oil smudge and dirt from breaker plate.
IMPORTANT: Carefully wipe protective film from
point set prior to installation.
4. Place a small amount of Distributor Cam Lubri-
cant on distributor cam.
5. Place new contact point assembly in position on
breaker plate and install attaching screw.
6. Check points for proper alignment. If points do not
align properly, replace with another set of points.
b
a - Lateral Misalignment
b - Proper Lateral Alignment
7. Connect primary and condenser lead wires to ter-
minal on contact point set.
Index
4B - 6 - IGNITION SYSTEM
a
8. Check point spring tension (20-27 oz.) 567-765g.
a - Movable Contact
b - Spring Tension Gauge
Contact point pressure must fall within specified limits
(Step 8, preceding ). Weak tension will cause chatter
which results in arcing and burning of points and an
ignition miss at high speed, while excessive tension
will cause undue wear of contact points, cam and rub-
bing block. Contact point pressure should be checked
with a spring gauge. Scale should be hooked to
breaker lever, and pull exerted at 90 to breaker level.
Reading should be taken just as points separate.
Pressure can be adjusted by bending breaker level
spring. If pressure is excessive, it can be decreased
by pinching spring carefully. To increase pressure, re-
move lever from distributor so that spring can be bent
away from lever. Avoid excessive spring distortion.
IMPORTANT: Point gap or (dwell) can be adjusted
by 2 methods. It is preferred that points be ad-
justed with a feeler gauge, then checked with a
dwell meter. Points, however, also can be ad-
justed, as well as checked, with a dwell meter: Af-
ter points have been set, dwell should be checked
with engine running.
50641
90-816462 2-695