tophatyachts.com

Probably too big for a Top Hat, but someone's flogging a Yanmar 2GM20, saw the notice in the window of the Yaringa Marina chandlery. Says "low hours" $2500.

Cheers, lockie

I have one in my MK 2 and it fits comfortably. The extra power is handy in a headwind.

Bart

Boy, a 20HP in a Top Hat would sure move along!

I have the 15HP Yanmar twin (2QM15) in my Tophat that was superseded by the 2GM20 and it fits fine. I have found the extra HP very handy when things go pair shaped. They say a well serviced Yanmar will run 10,000 hours between rebuilds. At the rate most yachties use their motors (50-100 hrs a year) this equates to 100 years of sailing!

Cheers,
Mark

I don't know about getting that much service from a marine diesel. They're one of the most abused items in the boat. THey sit around in salt water, rusty, very little maintenence, expected to start first time every time even when used every month or so. They're even stuck in the lowest part of the boat in the worst environment you could get. I saw a picture of a Farr 40 being built at McConachies (?) yard. The hull fit out had just started and the engine was already in before the deck went on.
I believe that Yanmar have a steel alloy that doesn't need anodes even using raw water cooling.
I have had a Hatz (BMW) and a Volvo both 12 HP and the extra power is great when needed.
Would the 20HP be too heavy? I think the Volvo is heavy for a Top Hat.
Greg.

Hi Guys

Bears Views for the last time in 2010 !

See 'Bears top 10 ' that's where a 20 hp belongs 7hp - 12hp is all thats required .If you want to go faster buy a motorsailer or better still a stink boat.

Not sure about Ynmars not needing anodes - my 2GM sure does.

Greg,
Inboard diesels need anodes!!?, just when I was starting to relax about having an Inboard instead of an outboard, yet more complications, thanks for the heads up, I'll investigate where my anode is, or more likely should be.
cheers
Shaun

Hi All, re anodes, I said that "I believe that Yanmar have developed an alloy that doesn't need anodes".

Most diesels have TWO anodes, one near the top of the engine near the thermostat and one at the bottom of the cooling jacket. They will just look like a bolt with a copper washer or gasket under the head.
You can make your own but its best to buy the original spares. They have a steel insert moulded into the anode that makes it more robust. The Hatz had an M10 set and a 3/8 UNC set (confusing).

Best of luck finding it.
Greg

Anodes:
Yep, my Yanmar also has two anodes. They only need to be replaced every few years, though should be checked each year or two. When I took my front one out last service the zinc had worked its way out of the bolt so it was doing squat to protect the donk.

Weight:
The 2GM20 is about 110kg. My old 2QM15 is 145Kg and the boat still sails OK(second place in recent Tophat regatta despite dragging my off-centre two blade prop through the water). Outboards have their weight much further aft and probably affect the way the boat lies to it lines just as much as an inboard.

Too much power:
I think Bear is right that 8-12HP is fine for a Tophat. My diesel begins to cavitate the prop when it is run flat out, but I think the choice of engine depends on how you use your boat. I prefer the torque, sound, reliability, fuel efficiency, safety and convenience of the inboard diesel. I also have a tank that is big enough to run the donk for 40 hours if need be. Heck I even don't mind the slight smell. Whenever I pass a tractor I think about being out on my boat. Mind you having said all that I would consider repowering, when the time comes, with an electric motor.

Happy New Year,
Mark