Some ignition failures can be cause by battery chargers

Also poor connections on electrical & or ignition sides of the systems causing resistance and spikes. Corrosion as well.

Improper sized cables and wiring

heat

vibration

Just keep this in mind. When I was a contractor at Depot they did a survey. If you do a super good over the top job maybe the customer will tell 5 people. If you do a bad job in anyway they will tell 33+ people. Pro Comp was junk. Now Eagle is junk and Pro Comp is the preferred crank. If I said that on a crank thread even though I have had more then one machinist tell me this along with personal experience Pro Comp would be called junk in the very next reply.
Like said. Mount the box proper and they do also make a marine version like the circle track version I use that is filled with gue to stop the boards from shaking apart. If you are using one that belongs in a car in a marine environment you get what you get.

No more anything MSD for me. I ran them years ago on boats and such, and had fairly good results. I built a rockcrawler fairly recently and used their distributor and 6A Offroad box. First box left me about 4 miles into a trail in Oklahoma. Get out hours and hours later, put in a call to MSD, "yeah, we've seen some failures with that box, send it in". Fluke? I send it in, wait several weeks to get another back. Cool. But it dies again. I will cut a super long story short(er), I had several die, at intervals of 2 months to 1 year, so I ended up buying a second box so I'd have a box to put on it when the other died and was in transit. I was on a week long trip, BOTH died and left me in BFE. Got back, pulled it all (inside of dist. was rusted) and put in a DUI. Ran way better, 7 years not one issue.

In my opinion(I know mine) I dont see any reason to run anything MSD, boxes fail without warning, dist corrode to the point a 1 year old one looks like came from WW1. We have run many of the HEI's with a petronix dial rev limiter with zero failures for many years. The DUI's are great, not sure if they last longer than the less than $100 ones you can get from summit, jegs etc or not, cant answer that, but in a nut shell the old HEI's are very reliable and the HP ones work great at the RPM's we turn marine engines

Sounds like a good time. Ouch.

Ive ran my DUI for four years now with zero issues. I boat in salt water maybe 10% of the time and the internals still look brand new, which raises the question of what the f*** is MSDs problem. It may not impress everybody here but I’m stoked with it.

I run a 25 year old 6m2 box that has spent the night under salt water twice, and a pro billet distributer that's 14 years old and has been under salt water for a night along with the msd coil I still run. I've never understood the bash msd posts, except maybe the fit of the rotor in the cap which once addressed isn't a problem.

I guess it didn't have power on under water did it?

I ran a MSD 6AL in my previous Challenger. Mounted to transom with supplied rubber isolators. 12v power leads ran directly to battery. 1992 to 2014 when sold to donzimatt. I never had a problem. Same goes for the Blaster 3 coil used.

Maybe that's the key to longevity. Soak all MSD components in salt water. Overnight for distributors and coils, two nights for all electronic components.https://www.offshoreonly.com/forums/...ons/icon10.gif

Msd = JUNK, i loved msd products until 6 or 8 years ago. The old ones were better i think. I had a 6btm, lasted 10 years till it was dropped 6 feet at a dyno session where it fell off a ladder when taking everything apart.
So, i bought a msd 6m marine box, pile of crap. I don't remember the exact order of failures or problems but the condensed version is one of them wouldnt Rev over 4200 no matter what chip was in it, mounted on rubber, with a capacitor to smooth out voltage , on fibreglass, from the minute it was installed. The warranty box that replaced it would cut in and out randomly. When i got the THIRD box to replace that second box , i invested in a msd tester. Its a little signal generator you can clip to a box (anybodys ignition box) and make it fire w/o even installing it in boat. I still had the first two boxes i hadnt sent back yet. So i bench tested all 3, box one went on a rev limiter at 4200 even w chip removed, box two would break up if you tapped on it while test firing it. Box 3, right out of package wouldnt fire at all but if you wiggled the harness where it entered box it would fire. I called msd tech line, retards kept telling me i had a electrical issue with boat, i laughed, tried to explain to him the problems i saw bench testing them in a controlled enviroment. Super tard tech guy at msd never even heard of a msd tester. I asked him if they wanted the serial numbers off them because they must have had a bad batch, he didnt give two ****s, said the numbers didnt mean anything. I bought a crane box to replace them, testing it with msd tester i could leave it firing at 10,000 rpms on bench and a hour later was still going strong. Boxed all that garbage up and sent it back.
Was NOT a install problem, i dont BASH them for no reason, just junk ass garbage! Have never bought anything msd since, Smitty