Could anyone please tell me how much quieter and smoother the 2 GM20 is over the 1 GM? I have a 1982 Hunter 27 and am thinking of changing the engine to the 2 GM20. Will this make a big difference? If it is worth the change, does anyone know if it will go in easily, without too many modifications? Thanks! Don
Changing Engine
- Thread starter Don3086
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Before You Do That
Check with Mack Boring or other Yanmar distributor about changing out the engine mounts to later style engine-specific Yanmar mounts. Supposed to make a large difference. PS: I had a single Yanmar and looked at a twin in another boat. Not all that much difference. Rick D.
Check with Mack Boring or other Yanmar distributor about changing out the engine mounts to later style engine-specific Yanmar mounts. Supposed to make a large difference. PS: I had a single Yanmar and looked at a twin in another boat. Not all that much difference. Rick D.
Maybe alignment
The motor mount change was a good idea and alignment may also help. you may also try some sound deadening material but i suspect that the problem is more vibration form the one lung devil. The 2gms I have sailed have been a little noisy also. I just changed out my 3gm and it was "plug and play" which may not be the case for you. My old engine made the same racket as the new one until it died suddenly.
The motor mount change was a good idea and alignment may also help. you may also try some sound deadening material but i suspect that the problem is more vibration form the one lung devil. The 2gms I have sailed have been a little noisy also. I just changed out my 3gm and it was "plug and play" which may not be the case for you. My old engine made the same racket as the new one until it died suddenly.
Alignment and mounts are good.
I aligned the engine my self, It's near perfect. I've had people on board who thought it ran very smooth for a 1gm. There's a good chance, I may pickup this 2gm at a really good price. So if it is smoother and quieter and more powerful it may be worth it.
I aligned the engine my self, It's near perfect. I've had people on board who thought it ran very smooth for a 1gm. There's a good chance, I may pickup this 2gm at a really good price. So if it is smoother and quieter and more powerful it may be worth it.
1GM
Hey Don, I just bought a Hunter 27 with a bad YB8 that I'm planing on overhauling (or whatever preceeded the 1gm.) Are you looking to sell your old motor? I can be reached at njsrgb@yahoo.com
Hey Don, I just bought a Hunter 27 with a bad YB8 that I'm planing on overhauling (or whatever preceeded the 1gm.) Are you looking to sell your old motor? I can be reached at njsrgb@yahoo.com
diesels with less than 4 cylinders
sound like they want to fly apart. keeping them aligned does help.
sound like they want to fly apart. keeping them aligned does help.
YSM-12 out, Bukh In
When I purchased my 78h30 6 yrs ago, it had a single-cylinder YSM-12 which, as Deby so very well put it, sounded like it was constantly trying to fly apart and it darn near loosened everything on the boat! I went outside the box and installed a Danish-built Bukh 24hp 2-cyl, new shaft, strut and 3-blade prop. No problems...and for $8,000 start to finish, one would certainly hope so, wouldn't one?!
When I purchased my 78h30 6 yrs ago, it had a single-cylinder YSM-12 which, as Deby so very well put it, sounded like it was constantly trying to fly apart and it darn near loosened everything on the boat! I went outside the box and installed a Danish-built Bukh 24hp 2-cyl, new shaft, strut and 3-blade prop. No problems...and for $8,000 start to finish, one would certainly hope so, wouldn't one?!
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