I changed my engine from an old ford to a new Yanmar in 2008.
I thought you might like some pics as this is quite a tricky job
but not impossible by any means anyone who can use a tape measure an operate a spanner or wrench should be ok..
first problem was to get the old one out!
I basically pulled off / broke down the old engine as much as i could to shed the weight and get it out the hole. (under the sink)
then the local available muscle was called in to help me pull it out the hole, a lot of swearing and bruised fingers later we got it on the cabin sole.
So then after messing about with a frames and cum a longs , we found it was best to use the main halyard and some controlling lines to coax the old lump onto the jetty alongside, (I did the whole thing with the boat in the water)
Next step was to build a template to match the new engine, so that I could rework the engine bed to accept the new engine.(i still have jig / template will post to anyone who wants it yanmar part is $800 )
my only tip here is to measure measure measure the measure again !
Its really worth taking your time here!
Next step was to change engine beds , I put in several coach bolts and 10ltrs / 2.5 usgallons of bedding compound an sealed the wood with loads of epoxy to make a solid base.
in this pic you can see pink mason line which runs from centre of shaft forward to front of where engine will approx sit to get a reference.
Also a pointer to align placement.made from aluminium bolted to shaft fitting.
Anyway all of this was glassed over with structural roving very thickly!
(helps if you can find a assistant who can fit in the hole)
now you gott the base swing in the new engine and line up as per Nigel Caulder Book.
I got approx 1ft , 300mm shaft extension made so i didnt have to change shaft.
The only thing i forgot was that the yanmar runs opposite direction so I had to jump in water and swap prop to one that runs correct way.
Apparently you cant run gear box on yanmar full time in reverse because it doesn't pump oil over gears this way.
anyway hope this is of help to someone if you have any questions or need translation or want further advice pm me or post !
I got Yanmar to inspect work and they signed it all off gave me the warranty and offered me a job!
sail safe
regards
Tom
