Wiring diagram never existed.
Look for the generic information in the electrical forum. The wiring colors are an ABYC standard. And the wiring specific to the motor in the motor manual
You were told wrong
It didn't show more than 100 because there is no water in the block
With cooling water, your exhaust temp is 200f
Without cooling water, the exhaust temp is 1100f
Usually when the floor rots the stringers and transom rotted decades earlier
Check to see if the boat simply had a "deck-over"
Deck over defined: Slap plywood over the rotten deck and sell it asap (boating equivalent to 5# of bondo filling in rust at a used car lot)
