Noisy little diesel

[DoubleEnder]

I have a Yanmar 1GM10 in a small wooden sailing boat, 25 feet 2.25 tons displacement. It is plenty powerful enough but it is very noisy. There is a simple wooden box around the engine, no sound insulation and no room to add insulation. I could, at some considerable expense and trouble, construct a larger box, with some insulation but even then I think the noise would not be reduced by much: the rear of the engine and the gearbox is just under the wooden cockpit floor. I can't add insulation here without raising the cockpit floor....
I guess I just have to live with it. Noise cancelling earbuds help, and it encourages me to sail, not motor. But I am curious, how much quieter would one of the little 2 cylinder engines be? Eg Nanni, Beta, Vetus 10hp models?

 

[Tranona]

I replaced a 1GM with a Nanni 14 in a wooden boat with open bilges rather like yours. I insulated the engine box which reduced the noise a bit in the cabin. The Nanni was definitely quieter than the Yanmar but my aim in replacement was the additional power in the same physical size. I always found the Yanmar rather comforting on long runs - non stop from Alderney to Poole on one trip and a couple Poole Cherbourg. More worrying is the thought it might stop - which it did only once in the 10 years or so I had it. vast improvement over the quiet and smooth Stuart Turner P55ME it replaced.

 

[Slowtack]

I had a noisy GM10 once... Useful tip...to get a bit further from the racket tie the headsail sheets to the tiller and use them to steer sitting forward of the mast....

 

[garymalmgren]

There is only one thing worse than a noisy engine.
That is the sound of a dead engine when you really need it.

 

[Dellquay13]

I have a Yanmar 1GM10 in a small wooden sailing boat, 25 feet 2.25 tons displacement. It is plenty powerful enough but it is very noisy. There is a simple wooden box around the engine, no sound insulation and no room to add insulation. I could, at some considerable expense and trouble, construct a larger box, with some insulation but even then I think the noise would not be reduced by much: the rear of the engine and the gearbox is just under the wooden cockpit floor. I can't add insulation here without raising the cockpit floor....
I guess I just have to live with it. Noise cancelling earbuds help, and it encourages me to sail, not motor. But I am curious, how much quieter would one of the little 2 cylinder engines be? Eg Nanni, Beta, Vetus 10hp models?

My 1gm10 was a shock when I first started it, I was used to big modern 4cyl 4stroke outboards that are so smooth at tickover you need to put your hand on them to check they are running.

One of my first posts on here was asking if they always sound like a whacker plate levelling a gravel path

It is still noisy, but I have found it much more smooth and reassuring at 1/2 throttle and above. You expect some engine noise at that power, and being smoother it’s less annoying.
It’s also been too reliable to think about the disproportionate cost of fitting something else for a smoother low rev experience

 

[William_H]

It is not just the noise but the vibration of a single cylinder diesel. Yes a 2 cylinder will be a lot smoother and perhaps quieter. 3 cylinder even better. OP knows the answer. Put the sails up and stop the engine. ol'will

 

[Ian_Edwards]

I had a 10GM in my Parker 275. I fitted an Aquadrive between the gearbox and the propshaft, softer engine mounts and an additional Halyard expansion box in the exhaust.
The Parker already had reasonable sound insulation around the engine box, but the combination of isolating the engine vibration from the hull and propshaft and the extra "muffler" in the exhaust really quietened down the whole installation.
On tick over, you could hardly hear the engine from the pontoon.

 

[Snowgoose-1]

I find ear plugs effective on longer runs.

 

[Gixer]

I have a 1gm10 with the engine box lined with Polymeric sound insulation. People remark how quiet my engine sounds for a single cylinder. I can happily have a conversation at normal volume down below with the engine running. 100%, a modern design water cooled twin or triple would be better, but noise wouldn't be the reason I would change.