So had a great day out on the Chesapeake on Thursday 7/4/24. Did a 35 mile run. Perryville Md to Still Pond and back again. Put the boat on the trailer, great day out on the water.
Next morning, loading the gear on the boat and getting ready to tow it to the launch and I try to start it. Nothing, nada, no fire. She cranks, she's got fuel. Not so much even a sputter or cough. Pretty quickly I diagnose there is no spark.

Keep in mind I haven't made a change to the engine, wiring, or boat in several seasons. Carbureted 383 SBC with MSD 83606 RTR dizzy and blaster 2 coil. She always starts super easy and immediately.
Battery is new this year and strong. Cap, roto and wires new last season. So I start some basic troubleshooting.
Battery voltage is present at the coil's positive terminal when key is on. Battery voltage is present at coil's positive terminal when cranking. Per MSD's RTR troubleshooting, negative coil terminal to ground is also 12v. (https://www.holley.com/blog/post/msd...oubleshooting/)
So I run out to autozone and buy a new coil. Still no spark.

Confused and frustrated I have my 18yr old son (whos pretty handy) help. He's manning the helm while I'm straddling the engine. I'm measuring voltage between the positive coil terminal and engine ground again while he's cranking it. One time he tries to start it while I'm doing this and BAM she fires immediately like she always does. I pull the voltmeter leads off and she stumbles and dies.

So we repeat the above, and BAM she immediately comes to life. This time when I remove the probes, she stay running. Hooked up to water, I run the engine until it reaches operating temp. Shut it off. Try to start it, immediately comes to life. Shut it off, attempt to start, immediately comes to life. I repeat this maybe 20 times. Each time an immediate restart. We launch, goto a nearby island with friends who know they might be asked to tow us back in. After several hours at the island, she relights and we call it a day.

Sunday I tried to start the engine. No fire, same as before. Was on tech support with MSD this morning and they're telling me sounds like an ignition module in the base of the distributor. They wont sell me the part, want me to send the distributor back in for service 3-5 wk turn around time. A new RTR from MSD is $655.95 from summit.

My question is: anybody tried the Pertronics RTR stuff?

https://www.summitracing.com/parts/pnx-d200810

I would avoid Pertronics as I have had 4 fail in the last year.

drop a delco est external coil system in and go boating

Thanks for your reply, but do you mind elaborating? What happened?

Perkotronic

Thanks for the input guys, I ordered another MSD 83606

x 2
msd = my spark died

x3
junk yard distr.from 350 or 454's from 99-96 year trucks,,damn near bullet proof.

X4