Thanks guys for the lively discussion!
Hopefully I have my head screwed on right!
I happened to be using the boat when the starboard engine passed 3000 hours, and the next trip out we had to replace the powerhead with a used one the dealer had to get the boat up and running (still waiting to see what happened to the other powerhead).
Few days later I am running the boat (yesterday) and something happened that put us out for today and probably through Tuesday with the port engine, which I also watched just past the 3000 hrs. They just came out of 300hr service, but did one trip before I used the boat. It's also a long holiday weekend so the dealers are closed.
We have in the business plan the hourly reserve, but I was expecting another 500-1000 hours out of these.
I guess the question is whether to keep repairing and getting hit with costs, downtime and cancellations vs shelling out for new engines now. I will have to take out a loan to finance the engines.
I would also go to 300hp from the 250hp. I've been told this would be better for the boat performance, fuel usage, and longevity of the motors (assuming same cruising speed of 32-34 knots).
It's not all bad: