85 HP Chrysler running good and then just died

I have an 83 Bomber with a 85 HP Chrysler model# 857HD, MagnaPower with a distrubutor and one coil. I have been tinkering with it. Last week I rebuilt the carbs and timed it up and installed a used tach. The tach was tested and was good. I set the tach to P3 on the back switch. I took it to the lake to test it and it ran good. Ran it for about one hour. strong out of the hole and topped out at 4800 rpm. going back to the ramp it just died and would not hit a lick after that. I brought it home and started checking it out and I am to the coil test in the Seloc Manual. Across the terminals it should read on the meter less than 1 ohm it reads 2 ohms. And from the ground terminal on the coil to the spark plug wire should be 500 ohms, it reads open.

Question#1 Does this sound like the problem?

I have had about 8 boats and all of them had a kill switch, but I can not find one this thing.

Question#2 Am I missing something or is it possible this boat just doesn't have one?
Thanks,