I don't know jack about powerpacks but I did some investigating on the BFHP. It seems the typical symptom contains some misfiring or the engine starts to cut in and out, then followed by you not being able to gain more than say 2000RPM's. The reasons seemed to be varied and will probably need to be hooked up to a diagnostic machine. The most common problems seem to be a starter, coil ground, voltage regulator, timerbase, key switch, and even faulty spark plug wires. Type in "powerpack" on the "boats and motors" section and there is quite a bit of info. Best of luck Dave!
On some motors while its running you can take a timing light and check to see if the side the powerpack is running has spark.
Also once you find that some plug arent firing switch the packs to see if the problem stays or goes to the other side.
There is really no check for the power packs, but there is a check for the stator ,trigger and coils, using an ohm meter.
One pack runs one side of the v-6
Make sure your ground connection is good other wise they wont work and a bad ground cause's them to burn out also.
Sometimes your stator will make it seem like your powerpacks are out. Mr. Bass had that problem for a while turned out to be a few bad wires on the stator
If you have the merc kind that takes 2 packs for a v-6 I have about 8 here that you can use for a test.
Yeah, I've been looking at BFHP, BBC, iBoats, and a few others. Seem to all be pointing at the stator or pack. Just thought someone else might have another $.02 to add. Del, my motor has only one pack as far as I know. It's just a single module, unlike the Mercs with 2. Thanks guys...
I had one go out a few years ago....the engine slowly lost power and died. I was stuck at Saguaro at night with my son and two really nice guys came to my aid and towed me back in. I did not know it was a power pack and took it in to a boat shop near Power and Main (Not Floyds Marine but the other one) the guy said I had no compression and advised it would cost $4000 to rebuild my motor. I took it to another shop near 40th and baseline and he did a rebuild for $1500. He did not check the power pack or the compression but took my word that it was a compression problem because that is what I told him the problem was having relied on the other boat shops. Guess what happened when we tried to start it after the rebuild.....you guessed it....the power pack was out and so after spending an additional $200 I was off and running. Well I dont doubt the motor needed a rebuild anyway and I got a good motor out of it but I still wonder how long that thing would have run had I just put a new powerpack in it in the first place.