Not very but that's not unusual. They both came from different homes. Both have seen little use that's for sure by the condition under the cowl.
One came as direct PX to a main dealer being swapped for an opti to get more power (being the first listed), the other came on a small 14ft speed boat again with little use. It was advised as having a full service 10 mths ago and not used since. The seller actually sold it as spares or repairs to me as since the service he had never used it and when he tried to start it last week he got a click from the solenoid and nothing else. He got "a mate" to look at it who diagnosed it to need a re-wire and a new starter motor. His logic being the power is there due to the clicking, solenoid works as he got that click so it's the starter motor!!! Errr no...
I took it in and found all it actually needed was a battery terminal (I got lucky). The connection from lead to terminal was poor giving an intermittent connection. Once changed (£3) it fired up first time and ran sweet as a nut. The guy needs a new mate that's for sure!!!
They are the same weight as your 75hp motors... No joke! They will drop right on in place and provided yours is not the newer 14 pin adapter the controls will plug right in. Couldn't be a better match!
Hope that helps.
Peter @ Boatsandoutboards4sale ~ email@example.com
~ 07930 421007