I have a Mercury 50hp 2 stroke for 8 years - happy with it. Mercury have had quality issues in past no doubt - but some models are well regarded. My 10 cents worth? Better corrosion resistance than older Japanese motors of same age (I think the new ones now are all good), I like the styling, Also do you have a good dealer nearby? Certainly 4 strokes are more economical but if looking at buying an older motor 2 strokes are simpler and easier to maintain and will take more neglect. Having said that I would be wary of older optimax mercury and other fuel injected 2 strokes as they seemed to have to many issues in the past. It really comes down when buying second hand you have to look at what is on offer - check in with a local dealer and ask about the motor on offer as they will pick up servicing (or you can tell them that) are you happy with rig and how it goes? A careful owner who flushes after salt water use and regular servicing?. Genuine reason to sell - I dislike the guys who have thrashed boat for years and never done anything to it, say it never breaks down - means it due to go toes up on you!
Regardless of what you buy check it out first carefully as you can burn a lot of money buying a dud. My experience buying secondhand is I usually look for a few weeks and many boats before I find one I like. Cheers

I had a 2007 90hp for six years without a problem except for the solenoid which was replaced under warranty. They are a big volume motor at 1400cc but do run a little rough at idle but you get used to it.

They do as standard come with an SS prop which gives a little better performance.

I would and do have another Merc.

Thanks for the feedback so far guys. At least I've got a few things to look for when I go and have a gander. Anyone else?

Apparently we're looking at a 1 quite pedantic owner less than 50 hours and serviced every 12 months.

I have the 115 version, probably same block. 

Retired careful owner is gold!
However do a compression test (a shop can do for you) if not used much may have corrosion issues, they like to be used regularly like any motor and regularly warmed up, though that said 300 hrs is bang on regular use over that time - I have been told my Merc 50hp should be good for 2000 to 3000 hours and has now done 300hrs in 8 years. Cheers

Ramco also have a "Dominator" that's my boat the motor was a perfect match.

Old thread i know but looking at a 05 merc 90 2 stroke done 200 hrs 6k fitted to boat all gauges and remote........thoughts plse