I found a boat that has twin 525 with blowers, and driven by TRS drives. The concern that I have is that the boat has not been run since 04. It was winterized and shrink wrapped and left forgotten. What kind of issues can I expect? Will these run if I give it power and gas? FYI. Motors and about 150 hours drives and transmissions unknown but estimated 300. Over all this boat has been well cared for, but for family reasons not touched since 04.

Which 525s?At least put fresh gas in it and spark plugs.

should i be concerned about any internal problems? 525 merks

What kind of boat? With a heavy boat you might be more concerned about the drives, TRS I believe are hard to find parts for, and you can only rebuild them, not get new ones.

Yes, I am concerned about the drives. it's an Apache with TRS drives.

Mercury had 2 different 525s.One was a supercharged 454 from around the late 80s to 90s

Are they 525EFI's with blowers or are the 525SC's??? Either way I would be more concerned about the fuel in the tanks than the trannys and drives. People don't give the trs drives the respect they have earned.

525 SC's

525 SC's

That package was very popular in it's day and should have no issues once you get it ready to run.
Change ALL fluids and filters in the engine AND tranny/drives then make sure you have fresh gas too. (probably need batteries also). Things should fire up and run after that.