I reviewed the troubleshooting page for Mercury at the
www.tenkillermarine.com website. It had some interesting information and a
couple suggestions.

I decided to send them an e-mail to see what they have to say since they
make a strong statement about helping Do-It-Yourselfers. Here is my e-mail
to them. Ithought i would copy it here and see if anybody in this group had
any insites into my trouble shooting processes.

******
I read through your trouble shooting page for Mercury Engines. I have a
1982 150 HP Black Max V-6.

Let me describe the running of the engine. It seems to lose power. I have
had it die about three times on me as well. I have always managed to get it
started again. A couple times it took a little while before it would start
back up.

In trying to trouble shoot this problem I redid the fuel line from the tank
to the engine and checked the lines from the pump to the carbs. I also
added a Racor Marine 2 Micron filter and water seperator. For the moment
the diaphram return spring is missing from the fuel pump. I turned it over
with the lines to the carbs disconencted and it pumped plenty of fuel. It
may be marginal at high rpm, but I don't think it is causing my problem. I
do have a new spring on the way. Just to be safe I'll put in a new diaphram
at the same time.

The most noticable symptom is that it will substantially lose power. I can
be cruising at any speed above planing speed. 2800 RPM or up. It will lose
power and the tach will drop several hundred RPM. I took it out on the lake
and ran it as hard as I could yesterday for an hour or so. The most
noticable was at full throttle. I could be running 4700 RPM and
accelerating and it wouldl drop suddenly to about 4000 RPM. At that
throttle position it would rarely pick back up. At lower speeds sometimes
it would kick back up for a few seconds. It performs similarly at lower
RPMs as well.

I read through your trouble shooting page and gleaned what could.

The 1st item was to disconnect the kill switches and check for DC voltage.
My meter shows 0.0 with the ignition off and 0.01 with the ignition switch
on. Your sheets say no voltage. Is .01 significant?

The next thing you mentioned was to check the stator for leaks and burn
marks. I found no signs of leaks or burn marks on the stator, but the top
of the engine has a small amount of oil puddled in the hollows on the top of
the engine. ALSO, one of the leads coming out of the stator is half bare
and corroded at the point were it exits the stator. It is not one of the
leads to the ignition packs, but one to the small module above the ignition
packs. It goes to the bottom center screw.

I checked the impedance of the white with black trace terminal on each pack
and they read 14,800 and 14,850 respectively to engine ground.

I'm not sure if this applies, but under "High Speed Miss" you say to
disconnect the rectifier and see if it continues to miss. I assume that is
the black box at the top front of the motor. If so do you reccommend
disconnecting all three leads or just the white with black trace wire?

Under intermittant missing you say to disconnect the white with black trace
jumper between the ignition packs. Do I also disconnect the one that goes
to the black box?

Obviously I need a new stator, but I want to figure out what else might need
replacing.

Oh, one more thing. The other day I used an inductive timing light to check
the spark on each cylinder. I got steady spark on all 6 cylinders, but it
seemed that the sparking rate reduced about half way though testing. Steady
spark, but at a slower rate. It was not a huge difference. I had a hard
time convincing myself there was a difference at first.

Suggestions?

Bob La Londe
Yuma, Az
http://yumabassman.4t.com