Engine Vibration

[Ron Hill]

Jack : I can't overstate how pleased I was when I change out from the OEM mounts. It had gotten to the point that in a long motor I would stand on a rubber cushion to prevent the "buzz" that was being transmitted to my feet.

I've had dockmasters and marina owners ask (when I told them to throw off the bow lines) "aren't you going to start your engine"?? It was already running !!

A few thoughts

[Carbon]

Second, where did you hear that "they work the best"??

Don't overthink this. K75s all around!

I didn't say "they work the best", I asked "if they work the best".

Logic would say that when these boats were new they must have had reasonable engine vibration. Otherwise Catalina would have done something different because it would have affected sales. Presumably stock engine mounts would put it back to like new levels which are probably pretty good. 

My other boat has a Yanmar 30Hp 3YM engine on stock Yanmar mounts. It's very smooth at idle and at motoring RPM. My experience in Yanmar world is that the stock mounts work well, I've never considered upgrading them to something better.

If the current consensus among C34 gurus is that Vetus K75 mounts work best, then that's an easy decision. They are not very expensive and in stock at Defender.

I do have a quote request out to a company called Oceanic Innovations. They make engine mounts, mostly for Yanmar, that have stainless and urethane construction. They don't stock mounts that will fit the M-25XP, but they have made them in the past. It would be a special order item, delivery might be a problem.

Urethane is unaffected by oil & diesel. Stainless obviously beats mild steel for rust. I'd like to see that quote. But, I've been waiting nearly a week for the quote, not sure it's ever going to come.

https://oceanicinnovations.store/collections/frontpage?gad_source=1

Jack



   

[waughoo]

The original mounts do not provide the same isolation that the vetus ones do.  I suspect you would not notice the same improvement in sound transmission to the hull if you did the stock mounts vs the vetus.

The Yanmar mounts (especially when coupled to a sail drive) are particularly good at isolating vibrations.  I suspect they spent more engineering resources to this part of their marinization vs Universal.

[KWKloeber]

Jack

Gotcha.  Now I understand what you meant, but that was a statement not a question, i.e., no "?", there.

The key issue with the OEM or other isolators is a leaky seawater pump that conveniently runs right onto that forward one. If there's diesel and else getting to mine I  have more of problem!  I'd expect a custom fab to be super costly, but I hope you get a quote so we know.

As far as the factory and OEM mounts, the fact is that Frank, like any production boat builder, cost was key and also remember supply chain availability.  One could say similar things about the Univesal's wiring, exploding alt mount, and other shortcomings -- or Catalina's own harness, the infamous Catalina port list and "off-plumb" keels, etc.  They did not seem to affect sales, only complaints long afterward.  Like 20 years later.

-Ken

Second, where did you hear that "they work the best"??

Don't overthink this. K75s all around!

I didn't say "they work the best", I asked "if they work the best".

Logic would say that when these boats were new they must have had reasonable engine vibration. Otherwise Catalina would have done something different because it would have affected sales. Presumably stock engine mounts would put it back to like new levels which are probably pretty good. 

My other boat has a Yanmar 30Hp 3YM engine on stock Yanmar mounts. It's very smooth at idle and at motoring RPM. My experience in Yanmar world is that the stock mounts work well, I've never considered upgrading them to something better.

If the current consensus among C34 gurus is that Vetus K75 mounts work best, then that's an easy decision. They are not very expensive and in stock at Defender.

I do have a quote request out to a company called Oceanic Innovations. They make engine mounts, mostly for Yanmar, that have stainless and urethane construction. They don't stock mounts that will fit the M-25XP, but they have made them in the past. It would be a special order item, delivery might be a problem.

Urethane is unaffected by oil & diesel. Stainless obviously beats mild steel for rust. I'd like to see that quote. But, I've been waiting nearly a week for the quote, not sure it's ever going to come.

https://oceanicinnovations.store/collections/frontpage?gad_source=1

Jack



   

[Ron Hill]

Guys : The engine mounts come with the engine!! No boat builder is going to put different engine mounts on a new engine and discard the ones that came with the engine. 

Ken you forgot the port side forward mount is below the Oil filter. Unless you take EXTREME CARE changing the filter - there will be old engine oil on that mount - which will Kill it!!

A few thoughts

[KWKloeber]

Thaanks Ron

I forgot about the isolators being delivered by Universal.  I'm not sure that in those years, K50s and K75s were even made.  Do you know?

On the drips, I wasn't including things that are under OUR control. Sure, I could spray diesel onto all of them if I was careless about changing a fuel hose.  I'm thinking that most? owners will be conscientious about not destroying isolators.

Guys : The engine mounts come with the engine!! No boat builder is going to put different engine mounts on a new engine and discard the ones that came with the engine. 

Ken you forgot the port side forward mount is below the Oil filter. Unless you take extreme care changing the filter - there will be old engine oil on that mount - which will Kill it!!

A few thoughts

[britinusa]

I changed out Eximius' Mounts with K75's around 2016, in 2024 Vibrations returned in 2024 so I replaced them again.
Didn't solve the issue, actually it was worse.

Had a mechanic check it out and he figured it was the Damper Plate. I replaced that and the vibrations / noise dramatically reduced. The old damper plate was shot, the springs were intact but were no longer providing any decent physical connection from the Flywheel to the Gearbox input.

I had never heard of a 'damper plate' prior to this.

Paul

[Jon W]

Hi Paul, what manufacturer and part number did you use for the replacement? How many hours do you have on your M25XP? Thanks.

[Ron Hill]

Jon : Look in the Mainsheet tech notes. When I changed to a Hurth 100 on the old M25XP I also changed to a new damper plate. I believe I mentioned the Model Number and the source.

A thought