I didn't make it to the boat this weekend. I have the gear box down as a KM2P 3.22. However the owner between me and the person who re-engined the boat changed the prop to match. I will definitely be on the boat next weekend so will take some pics. The length thing might be boat specific...the shaft log wouldn't need to be very much shorter for a stuffing box to fit.

I don't really see a need for an access panel. To get to the oil fill the piece of plywood behind the steps has to come off, and then to get the whole starboard side of the engine bay off is 2 or 3 more screws.

Thanks fcd,
Thanks Bill,

I have some beginning of answers from Macboring which Yanmar seems to use for its customer service in the US. But still waiting for the drawing with dimension of the original 2GM+KM2A.
I did measure over the week-end and found an exact match on the total length of engine+transmission and relative to silent-block attchement. So I am quite hopeful, but I am still a bit baffled of why the 2YM15+KM2P-1 would fit a J/30 model 79 and not a model 84. So your pic and model would help..

Regarding the propeler pitch adjustment if a KMP2P 3.22 was choose - it makes sense - but I intend to stay with the same ratio (2.62) as the original setup - as mentioned also Bill...

Will update the thread when/If I managed to have the original 2GM+ KM2A drawings...
Cheers,

Our boat (1982 #410) was repowered with a 2YM15 back in the mid 2000's long before we bought her. I could take some photos next time I'm at the boat if there's something specific you need to check. Our boat has both quarter berths and the low/no coaming cockpit.

Thanks B.
more pics can not hurt, but I am not sure it will give me more info than what Rob's photos showed.
The two open questions really are:
* is the engine setup similar on the v2 of the J/30 (~1984 coaming, bigger cockpit - and bigger 1" propeller shaft).
* how much drop-in is the replacement when you go with the full package (2YM15+KM2P-1).
And picture might not be as helpful (considering of the so many dimension fits involved) than knowing someone that actually did it. But I am already greatfull for the feedback so far... At some point I have to go for it and see how it goes... :-)