Yamaha 30 - YSM12 diesel engine - need new stainless steel wet muffler

[Blue Horizon]

Hello All,

I am in need of a new wet muffler for my Yamaha V-berth YSM12 diesel engine. I know that some have the standard steel muffler and many if not most of us have the stainless steel style. I've even seen one in a Yamaha 25 recently. Mine is starting to pit. I had a stainless welder put a patch on it but he said it wouldn't last long - he was right. Wondering if any of you know where you sourced your last one. Or ideas where to order them.

I did talk with Vetus at the Vancouver Boat Show this year and they don't really do anything that fits in that space under the v-berth.

Thanks!

Peter

 

[jssailem]

You may need to have one built. Local muffler shop doing marine exhaust work.

I’m having to do this on my boat.

 

[kloudie1]

Quick note; if you are looking towards custom stuff, consider using fiberglass, a much better material for that service.

 

[Johnb]

Are you sure you know whether you need a muffler or a mixing elbow?

And it’s a Yanmar not a Yamaha

 

[Ralph Johnstone]

I know that some have the standard steel muffler and many if not most of us have the stainless steel style.

I can only speak for Hunter, Cat, Bene, and a few other production boats I see at the boat shows, but they usually have fiberglass mufflers. Does your muffler look like this :

Or like this, as suggested by @Johnb :

 

[dlochner]

And it’s a Yanmar not a Yamaha

Back in the day, Yamaha made sailboats.

YAMAHA 30-1 - sailboatdata

It is thought that the YAMAHA-30 is based on the Norlin designed SCAMPI MKIII. A tall rig version was also available. I: 12.4m/40.68 J: 3.7m/12.14′ P: 18.8m/35.43′ E: 3.2m/10.5′

sailboatdata.com

 

[Tally Ho]

So, the engine is located in the V berth? That sounds like a strange place to mount an engine. Must require a very long shaft.

The water lift muffler in my O’Day 322 with a Yanmar 2GM20F engine is this old unit from Vetus. It feels like plastic.





Greg

 

[Blue Horizon]

You may need to have one built. Local muffler shop doing marine exhaust work.

I’m having to do this on my boat.

Hi JSSailem - thank you for your ideas here. Great thought! Did you get yours done? If so who did you take it to and what was the approx cost.

Thanks!

 

[Blue Horizon]

So, the engine is located in the V berth? That sounds like a strange place to mount an engine. Must require a very long shaft.

The water lift muffler in my O’Day 322 with a Yanmar 2GM20F engine is this old unit from Vetus. It feels like plastic.


View attachment 213097


Greg

It is an "unique" place to put an engine for sure The part thinking by Yamaha (yes it's a Yamaha 30 with a Yanmar engine) was with a full crew of racers and weight in the stern the engine would do well up front. It was actually quite beneficial when I rebuild the engine right in the boat. Lots of kneeling (also known as praying) but there's lots of engine access. Quieter running when in the cockpit.

The prop shaft is approximately 11 feet long!

 

[Blue Horizon]

I can only speak for Hunter, Cat, Bene, and a few other production boats I see at the boat shows, but they usually have fiberglass mufflers. Does your muffler look like this :

View attachment 213089


Or like this, as suggested by @Johnb :
View attachment 213090

Hi Ralph - thanks for your note. I think we might be in the same marina - is your boat in West Van? I'm there on Sat and if so be happy to say hello.

Mine looks quite a bit like that. Here's a couple of pics of the muffler. Engine is in the V-berth. It flows from the mixing elbow down into the upper entrance of the the muffler and exits at the low point of the muffler out to the exhaust hose. Sort of the opposite of what the fibreglass and plastic Vetus mufflers do. It's small - about 9" long and 7" in diameter. 316 stainless - guessing 1-2mm thickness.

Do you think that is the wet muffler or a marine resonator type of thing that is usually downstream of the wet muffler? Would be nice if that was a wet muffler. What brand is that?

Thanks for your note!

Cheers!

Peter

 

[Blue Horizon]

Are you sure you know whether you need a muffler or a mixing elbow?

And it’s a Yanmar not a Yamaha

Yes - good question because you're right you normally have to replace those pesky rusting mixing elbows before anything else. Thanks for that question. The mixing elbow is quite new. I have a spare new one so I wish it was that. It is indeed the wet muffler that is need of replacement. Confusing... it's Yamaha 30 sailboat with a Yanmar YSM12 engine. Tongue twister for sure!

Cheers!

Peter

 

[Ralph Johnstone]

Hi Peter,

Just returned from a few days at Port Graves and then back to Snug Cove before returning to Thunderbird Marina. Sorry I won't be there for Saturday and regret missing the wiener fest on Saturday afternoon. Few chores to catch up on around the house.

Would be nice if that was a wet muffler. What brand is that?

It's definitely a muffler. A resonator ? This is more likely found on high performance automotive engines for frequency alteration before entering the muffler. Do not have the brand name of the wet muffler in any of the docs around the house so I'll have to let you know when I get to the the boat in a few days.

It's small - about 9" long and 7" in diameter. 316 stainless - guessing 1-2mm thickness.

From corrosion studies I have taken way back in the day, I don't think you could do worse than having a thin wall SS muffler (of any type SS) trying to handle a soup of elemental carbon, CO2 and salt water. I think the fact yours has developed a leak tells the tale. A FG muffler would have far greater success in standing up to that corrosive environment. By comparison, I have 2200 hrs. on my FG muffler shown in post #5 and it's still solid.

I'll let you know about the mfg. of the muffler.

 

[dlochner]

Centek Marine is a major supplier of wet exhaust mufflers. They literally have pages of them. One of them should fit your needs.

Category: Propulsion Wet Exhaust

Since 1962, Centek has engineered and produced the best exhaust systems for the best boats in the world. We have seen it all and have a solution that will work perfectly for your application.

centekmarine.com

 

[Ralph Johnstone]

Finally cleared out the aft berth and got a photo of what Hunter used back in the day :

I'd try to find a FG muffler locally as shipping costs across the border are pretty much up there with the cost of the ordered item.

Don't fall for the SS muffler scam as it is either the result of the mfg. not knowing that SS is not suitable for a wet muffler or just a cheap product.

 

[Blue Horizon]

Thanks Ralph and others! I got thinking about it and you’re absolutely right. The stainless doesn’t get a chance to oxidize as stainless likes to in clear air. So I’ve pivoted to looking at a Centek brand fibreglass lift muffler. It’s a bit of extra routing with in/out at the top but there is one that looks like it will fit fine. Way cheaper than the $2600 CDN quote to fabricate a stainless steel one. And I prefer the fibreglass route. I’m going to chat with them this coming week to confirm it’s right for the application.

Thanks all!