Evinrude 4906B 4HP 1969 Owner's Manual page 26

2-1 INTRODUCTION
The efficiency, reliability,
and enjoyment available from engine perfor-
mance are all directly
it tuned properly. The importance
forming service work in the sequence detail-
ed in this chapter cannot be over emphasiz-
ed. Before making any adjustments,
the Specifications in the Appendix.
rely on memory when making critical
justments.
Before beginning
check to be sure the engine has satisfactory
compression. An engine with worn or bro-
ken piston rings, burned pistons, or badly
scored cylinder walls,
perform properly no matter
and expense is spent on the tune-up.
Damaged piston, probably
mixture, or improper point setting.
TUNING
fuel economy
dependent on having
of per-
check
NEVER
ad-
to tune any engine,
cannot be made to
how much time
Poor
caused by
inaccurate fuel
2
compression must be corrected
up will not give the desired results.
The opposite of poor compression
be to consider good compression as evidence
of a satisfactory
not necessarily
an outboard engine.
mechanic has discovered,
compression check will indicate a satisfac-
tory cylinder, but after
and an inspection
require service.
A clean exterior
owner's pride in his unit.
lubricated and properly
deserved for
enjoyment
or the tune-
cylinder. However, this is
the case, when working on
As the professional
many times
the head is pulled
made, the cylinder
engine appearance reflects
Keeping the interior
adjusted will give
his investment.
would
the
will
this
well
him the