There are 4 items that are candidates for failure. (1) Depending on model
the stator should produce a specific voltage usually around 165 between
certain leads as measured with a DVA. (a special meter that reads peak
voltages and stores the readings). (2) A bad rectifier. You can disconnect
the rectifier and crank the engine. OFTEN if this is the problem you will
get spark. (3) A bad pack, unfortunately there is a long detailed sequence
for testing the pack on the engine if you have a DVA meter and the procedure
that is unique to your specific engine. (4) A bad trigger, again this
requires a DVA and the specific procedure for your engine.

Unfortunately many marine mechanics are not equipped with the tools and
procedures to resolve this problem efficiently. As a result it is common to
replace one part at a time until they finally stumble onto the defective
part. Once electrical parts are purchased or pulled from stock they are not
usually returnable.

The procedures are more guarded that the gold at Ft Knox! Basically because
a good mechanic can make good money resolving these types of ignition
problems AFTER several other mechanics have tried and failed! Hence they
keep these procedure to themselves as their "ace in the hole" to help them
earn a living.

The cost of a DVA is several hundred dollars, and while it is also useful as
a VOM it is a rather expensive item to have to resole trouble on one engine.

The bottom line is If you live in the Kansas City area a mechanic friend can
resolve the problem. If you live elsewhere you may want to find a good
mechanic who is skilled with Merk Thunderbolt Ignition Systems, has a DVA
and the RAPAIR procedures.

Another way to look at it is to simply purchase all 4 components and do the
labor yourself. (Stator, Rectifier, Trigger, and Power Pack [Switch Box]).
While this can be expensive, it is often the cheapest route especially if
your mechanic does that anyway, one part at a time You might just as well
buy all the parts up front and do the labor yourself.

Again, the only easily tested component is the rectifier.

Hope this bad news helps.

Don Dando


"jocast" wrote in message
ups.com...
Hello
i just bought a used 50hp mercury and they told me that the power pack
was not working fine. so i bougt one, i exchanged it but the problem
still there. It is not sparking what else could be worng?
or how can i check if the power packc are good i have 3 PP's i already
tried them and nothing. any ideas.

How can i test the PP's?