Good afternoon from the UK.

Looking at buying a second hand boat with reported 120 hours on everything. Comes with a pair of staggered Mercury 525 efi from I believe 2008/2009. Boat has sat barely used for around 5 years with periodic starting on the trailer by the sellers mechanic, currently winterized. Im trying to put together a list of things to check over. So far:

Engine scan for hours and faults etc...
Compression test.
Leakdown test.
All exhaust headers pressure tested.

Was thinking of an oil sample test where you send samples of the fluids away to a lab for testing but engines have recently had a service so this may tell me nothing.

Anything else I should look at with the engines? I don't have serial numbers currently but any rough guidance is appreciated.

Cheers!