I have seen several posts with people having bogging problems with 580 EFI sleds, but I haven't read where anyone has found the cause and cured it.

Well now I am having this problem. It's a '95 580 EFI Pantera that went in the drink a couple years ago. I finally have it back together, and I am experiencing a low speed partial throttle bog. If you nail it from a dead dig it seems to run right past the troubled area and it really screams.

The sled was running when it went in and it appears that components that had power running to them (from the battery) while under water were damaged. I had to change the following to get it running.

ECU - Yep, I got the blue dot to match my injectors.
Fuel pump relay.
Fuel pump.

So, what do you all think?

I have seen several posts where people are describing similar problems. Is anybody finding the solution?

Ken.

I have done a lot of reading and I have come to the conclusion that I should probably rule out the kill switch. I can't just disconnect it, can I? Don't I need to jumper something.

The biggest problem is a lower speeds, partial throttle. While it's doing it I get sort of a surging.

As I have said, if I just nail it wide open from a dead dig the thing runs really good. But if I take off in a normal fashion I get the bogging and hesitation. If I feather the throttle and get it past 6000 RPM or so it takes right off.

I should probably add that it does this while on a test stand as well. You don't have to be riding it to experience it. (I think that rules out clutching.)

Yah, you can bypass the kill switch. That little switch causes a lot of problems. You will have to use you key to shut it down... It's not a long tirm fix, but you can a least rule it out before just replacing it.
I would lean more towards that at first. Mine did the same thing last year.
But I have also had a bad belt do the same thing.
You can launch the sled fullout but as soon as it gets up to speed it cuts out?? Or is it a midrange bog??
Midrange I would say belt!
Have you ever run injector cleaner through the sled??