The J/92 Heart of Gold is named after the spaceship that Zaphod & Trillium stole in The Hitchhikers Guide to the Galaxy.
Like it’s namesake it is also powered by The Infinite Improbability Drive ( well 12 hp Yanmar Diesel actually (Upgraded in 2015 to a 2YM15 from the stock 1GM10) ).
The J/92 was introduced in 1992 and was one of the early “Sprit” boats that had a retractable bowsprit and flew an asymmetrical spinnaker.
I also know where my towel is.
Dimensions
DSPL 5,500 lbs LOA 30.0 ft ( 92 Decimeters )
Lead Keel 2,275 lbs ( 41% ) LWL 25.8 ft
Draft 5.9 ft Beam 10.0 ft
Sail Area (100%) 470 sq.ft.
Sail Area/DSPL 24
Before Heart of Gold there was The J/80 Mostly Harmless
Here Comes Mostly Harmless
Cruising in San Francisco Bay
Light Boat + Big Spin = Much Fun
And Away We Go Again
c/m
Boating Safety Tips, Tricks & Thoughts from Captnmike 
awesome boats!
I love the Hitchikers Guide references. I liked your site before that, but this makes it even better.
Thanks –
Heart of Gold is more obscure than Mostly Harmless, but when I start talking about the Infinite Improbably Drive people get a strange look on their face, with Mostly Harmless people would sail by and ask if I knew where my towel was, and when I replied “sure” my crew got even a bit more puzzled. But great boats
Hey, I was wondering if you might be able to offer any info on how the repower went when you upgraded to the 2YM15? I am the owner of hull #66 and am seriously considering it now rather than sinking any more money into keeping the 1GM10 limping along. I do a fair amount of motoring to get to/from out of town races and it’s already left me hanging more than once.
Looks like the new configuration will be slightly longer than the old. Did you have to do anything with the prop shaft? Width-wise, it looks like it fits exactly the same, but the rear mounts probably sit further back than the previous one. Any snags getting it to fit in place?
Any tips / info would be much appreciated.
I did the engineering and much of the work myself – not trivial – but I did not think too bad – been going to make a post of what happened
Yard manager said “smoothest repower he had ever seen”
(Just saw this is a comment – so will finish and paste this into the comment section)
2YM15 is wider on the port side – had to move the post side of the engine compartment out 1.5 inches – made a new frame with a gigantic side panel to work in the engine – sort of like a picture frame or frame around a window – made out of marine ply. Clamped the new frame in place and drilled 3/8 inch body fit holes into the old area around the access (3/8 drill bit) – did body fit in case something moved when I cut part of the side out of the engine compartment – nothing moved – secured I thing with 3/8 in St. St. carriage bolts I think – pictures are way in the archive – big access – held in place with bolts/thumbscrews – put brass threaded inserts for the thumbscrews –
Put in new PYI Dripless packing
New shaft – the old one could have been reused with some machining but did want old parts
New cutless bearing by yard – alignment is important
Replaced folding prop with new feathering Max-Prop (works much nicer – better acceleration and stopping
The prop spins faster than the old stock gearing – faster recommended by PYI prop folks to have less pitch in propeller
2YM15 is taller – transmission was too high – switched to “medium height” fancy motor mounts and no issue
Had to cur out the area below the front access panel (under the ladder behind the icebox – memory is foggy but 4 or 5 inches I think – used a router and sort of looks like medium crap – but I had a piece of stainless bent to cover up my wobbles – I think 10 gauge or so – held in place with some
Moved the engine as far forward as possible – which blocked access to water pump impeller – the removable St. St. piece fixed access to front of the engine – unlimited access now – had to make a new forward engine access panel
The 2YM15 is about 65 pounds heavier I think – moving engine forward helped to reduce the effect of the weight a bit
left Starboard side as is – stock engine access panel is small but enough room to change the oil filter and any other starboard needs.
Water lift muffler moved outside the engine compartment – aft of compartment opposite the fuel tank – the fuel tank prevented easy mounting of the muffler and did not just want to screw something into the frame – so made a fiberglass panel to hold the muffler then mounted the fiberglass panel to the center piece using Weld Mount fitting (they use a special quick setting adhesive and come in a stud like configuration (and many other versions including mounts for wire ties) – so no drilling into the frame – I roughed up the fiberglass and cleaned where the fitting were going to –
New exhaust hose that was rerouted higher to protect from following seas – Yanmar and Yard manager recommendation – top of hose goes up to the bottom inside where you sit and mounts to the side of the cockpit wall – I used lots of Weld Mount fitting – the hose was very stiff to work with and took extra mounts to keep in place and reduce the loading on each mount
The 1GM10 came out fairly easily but the boat was in the water so I secured the shaft so the boat would not sink
The alignment was done by the mechanic at the yard – they had added him recently and he was much better than the previous “mechanic” –
I had the yard do the alignment and mounting etc. so there was no “per direction of owner” on the work order – so if there had been any problems the yard would have owned the whole job
the hooking up of fuel and commissioning of the engine was by the company I bought the engine from.
During sea trials we put the boat up on a plane at full stop up on throttle
Later I had the cables replaced as they were getting a bit old
Engine control panel – new with engine – I filled in the hole where the old control panel was and cut new holes for the panel so the panel is recessed like the original – some people just put in a plate to cover the old holes but that moved the new panel out where I did not like it – after I repaired the old mount area I painted it white inside the recess and did the color change at the edge of the recess so nobody noticed the slight difference in color.
I did all the woodworking stuff myself – a friend was a contractor and was kind enough to let me use his shop for a few days to make the parts and paint/stain them
This is about all I can remember at this time and it is getting past my bedtime – but this should give you something to think about
yes motors very nice and less prop walk in reverse
Good luck
Wow, thanks so much for all the detail. I had a 8-10 week window where I was considering maybe trying this, but after reading that I definitely will wait until the next spring haul out before even thinking about it.
Also, sounds like the 2YM15 is not really as easy a swap as I’d been led to believe. I may research the Nanni N2.10 a bit more as they claim it’s a “drop in replacement” for the 1GM10. Suspect it’s going to be hard to get ahold of one, though.
Anyway, thanks again for all the info. Will be a huge help one of these days with properly planning out things.
The 2YM15 swap was not too bad BUT a lot of details to get right, yes a bolt in swap would have been easier, the 2YM15 is freshwater cooled so better temperature control and corrosion control, just remember to change the coolant I think every two years Yanmar recommends.
Glad I could help, wanted to make sure I had a complete list of what I encountered to reduce any surprises someone else doing the same swap.
Good luck