Sod it.
I've decided to continue in the tradition I started with my 2010 Tohatsu 20hp 4 stroke.
Yearly service - oil filter, fuel filter gear oil and engine oil change to follow.
Got plenty of engine oil in the garage so all in 25 quid to do the service.
Cheap for the peace of mind.
I did get my ear chewed earlier this morning from the Mrs when she checked her emails and observed the PayPal transactions.
I did turn it around with the safety at sea / maintaining your equipment talk.
It seemed to work