2007 Year Optimax 175. Installed March 2008
On the last couple of times out I thought the engine sounded 'different' ,, a bit of a 'strange noise' but otherwise no problem, lack of power etc .
I have for some time wondered about the air compressor as a 'wear' item and worried about the consequences of it failing at sea or catastrophically and causing serious damage to the block etc ? Air pressures were checked and find at last service in Feb 2014 at 702 hrs
The compressor has had a number of changes and supersessions over the years to 'resolve' a design/manufacturing problem
Anyway - power of the internet I found this bit of diagnostics :-)
This was my clickety clack ! even if not quite so pronounced
New compressor ordered and fitted - and thankfully the right diagnosis ( I'm often accused of being ocd with baby !)
Photos show the debris inside the old unit
Changed oil return lines as a precaution and thankful to my local mercury man for opening on a Saturday football day !
For those others with an Optimax, worth checking I would suggest.