another question,

would a coil from a new merc 80 work on the 72? say perhaps a 1978-1980
80hp coil?


"Chris" wrote in message
. ..
Hello there,

As far as troubleshooting so far I've been using the clymer shop manual
for 1972-1989 45-225hp, as well as mercury service manual of the early 70s
vintage that covers the motor to some extent as well.

The interesting thing is that the switchbox on this motor is not one that
has the white post. Actually due to the serial number in the 319 level
the box has only 4 posts - red, blue, green, and brown (based on the book,
and from what I've seen). The service manual suggests a different way for
testing outside of using the key on and white to 12+. (The other serial
numbers use that type of check though). The way includes putting #1 to
TDC, and grounding the blue on the switch box, removing the ground and
thus triggering a spark to #1. Well this didn't work.

I'm amazed at how to properly check the coil and switch someone still
needs to take it to a mercury dealer for the use of a special tool. With
all the advances in technology, and cheap technology at that, I'd think
there would be a way to test this with one of today's gadgets you pickup
at the local automotive shop.. but I suppose not....

So the next steps over the next 1-2 weeks is to get the parts into a
dealer and have them checked with this special tool....

C



"Clams Canino" wrote in message
ink.net...
And if you wish - I can talk you through a troubleshoot of the ignition.

1st test: Red on the switchbox (starbord side of box) outta be at +12 all
the time, when you turn the key on white will go +12. Switch is now
tested.
Let me know when you get that far.

-W

"Clams Canino" wrote in message
ink.net...
I have every part that motor could ever need - used and in stock.

-W

"Chris" wrote in message
. ..
hi there,

I've been tinkering with a 1972 80hp merc that I got some time ago
that
started, but has since failed to. It appears there may be a problem
in
either the switch, and / or coil. Based on the prices of these old
parts
it
could be pretty pricey if they both need replacing (which I wouldn't
doubt).
My alternative to just not fixing it, is to get another motor that is
newer
and in good working condition for a bit more. I'm keeping my eye out
on
those prices too, but have an important question to consider... Could
I
use
a smaller motor?

This old 80hp has powered a 15.5 ft fiberglass boat. But could a
newer
motor of a smaller HP do an equal or pretty good job? Perhaps a 40hp
of
a
newer vintage?

Has anyone had experience changing motor sizes?

Chris