Intermittet rough running

Hi everyone!

I have a problem that is driving me nuts.
92 Four Winns with 7.4L and King Cobra

It usually runns great, but occaisionally it will run very rough above 2k RPM. When it does this it doesn't matter whether it is under load or not. When it starts missing, it will also run hotter (205) and it heats up after it starts missing....not before. I can always limp it back to dock and it always starts right up if I shut it down.
The problem is intermittent and that's where I'm stumped.
I've been through Dons fuel troubleshooting and everything is in order...clean fuel, new fuel/water seperator, clean tank breather, rebuilt carb, proper fuel pressure so I'm thinking that it must be electrical.
I replaced the plugs last year and they looked good and the wires were new about 50 hrs ago and they still look good.

Thanks for your help and expertise!

Wayne

Re: Intermittet rough running

Doesn't anyone have a guess?

Wayne

Re: Intermittet rough running

Still no guesses?

Re: Intermittet rough running

Come on guys! I need your help!

Wayne

Re: Intermittet rough running

Do you have a multitester.Maybe run a check on coil performance during normal and bad running.

I'm no expert but I ,personally, would check it out.

Re: Intermittet rough running

You did not mention the cap and rotor being replaced, crossfire inside the cap can do what you describe although once it starts doing that it usually continues and is not intermittent. Sounds like something gets wet and causes cross firing or arcing somewhere.

Re: Intermittet rough running

Thanks guys for your input.

I have a new rotor and cap on order and I have done a resistance test on the the coil and it is between specs.
I really appreciate your help!
Wayne