2008 AR230 noise control

[Black Betty]

Folks, I read a few posts on how to make the angry hornets, that are the two engines, a bit more quiet. After much deliberation, I've ended up installing a false floor in the engine bay. The floor has enough ventilation gaps to allow for good air flow to the air cleaners and engine bay for potential fuel vapor build up to disperse and get sucked out by the vent pumps. The shelf is just a prototype and no sound matting installed yet but the difference if at least 50%! incredible. I've also taken to installing the pipe insulation along where the hood meets the body, only a slight noise drop so far.

 

[Acard7]

Post some photos dude! I plan on sound proofing this Spring.

 

[Black Betty]

These were the prototypes. I've since changed the design to a 3 panel system with dropping brackets on the back rest bolts. Photos when I knock off work in 10 days..

 

[Julian]

Mt only concern would be air starvation to the engines...but if you run the blowers that would solve that. Perhaps run a couple of hoses from the vents below to the engines if you have a problem.

 

[Black Betty]

Julian, definitely a concern. last trip had both engines maxed out around the 10K rpm at 42 Mph on the GPS so not too bad. But that's just one run. I'll continue 'product testing' to make sure that the girls keep breathing. Fuel vapors at rest are a concern at the moment as I've forgotten to run the blowers after stopping for lunch a couple of times. Thinking of installing a hydrocarbon detector (read about in other posts). Next on the list of sound deadening is the installation of two 'Fat sacs' in the tunnels beside the engines, Jeffs Jetboat type install. But the plan is to encase the bags in left over vinyl flooring to protect the sacs from screws and sharp fiberglass and to absorb some sound at the same time.

 

[Black Betty]

Folks, long time coming but here's my final set up for the noise control. All fittings and panelling made by me and designed to use existing fittings as I don't like drilling extra holes in my stuff (with the exception of the screws holding the shelf brackets into the carpeted side walls). You might notice the numerous gaps and extra wide 'holes', not by design but they allow for plenty of air to enter the engine bay for the engines to breathe.

 

[Ronnie]

I built a box around the engines of my 2006 sx 230 but decided to insulate the underside of the engine hatch on my 2010 242 instead. I think the box did a better job of absorbing the sound but also realize the 230’s engines put out a lot more noise since they spin up to 10k/10.2k rpm where as the 242’s spin up to 7.6k rpm.

I wasn’t concerned about getting enough air to the engines for operational purposes but was concerned about heat build up. I never noticed any performance degradation or excessive heat build up in either engine compartment. Not an apples to apples comparison but Think about how little free space there is an a Waverunners engine compartment with the same motor installed and Waverunners don’t have blowers.

I also found that on both boats it’s worth the time and effort it takes to seal the joints between the sides and front and back walls/bulkheads of the engine compartment. Stuffing the free space at the back of the compartments next to the engine compartment helps as well.

Yamaha Jet Boaters • View topic - Sound Insulation Installation

 

[Black Betty]

Ronnie, I'm thinking that yours and the pipe insulation from Jeffs Jetboat were the main inspirations for my decision on what to do. I'm currently stripping the sound mat off the hood but probably won't replace it with any noise cancelling material. I have a tiny bit of 'dynamat' left from a car sound deadening job which I might put on. Next step is to install a tunnel from vinyl floor mat and install 1 FatSac on each side of the engine bay, as per Jeff again. This should make it a bit quieter still.

 

[Manny252]

Ronnie, I'm thinking that yours and the pipe insulation from Jeffs Jetboat were the main inspirations for my decision on what to do. I'm currently stripping the sound mat off the hood but probably won't replace it with any noise cancelling material. I have a tiny bit of 'dynamat' left from a car sound deadening job which I might put on. Next step is to install a tunnel from vinyl floor mat and install 1 FatSac on each side of the engine bay, as per Jeff again. This should make it a bit quieter still.

WOW LOOKS MINT, SO DID IT MAKE A BIG DIFFERENCE WITH NOISE > WHAT ABOUT THE MUFFLERS ?

 

[Ronnie]

I thought it helped on both boats but the relative baseline noise is different between the two. It does not reduce the noise enough in my opinion.

There is a member here who added in line mufflers to his boat but it was not me and it is not a cut and clamp in place modification.

 

[Black Betty]

Thanks. The sound is definitely noticeably less but still inherently loud at high revs. I can't say that I've noticed many mentions of a mod for the mufflers but it does stand to reason that there's a lot of noise coming from those. Guessing that the logistics of sound attenuation in the muffler space would be a bit tricky with the limited access.

 

[zipper]

Here are 2 threads on wrapping the waterboxes. https://jetboaters.net/threads/sound-insulation-different-approach-harmonics-off-swim-deck-and-water-box-noise.7763/

https://jetboaters.net/threads/the-throttle-shifter-yamaha-should-have-put-on-our-boats.15940/page-2#post-274659

 

[tdonoughue]

Down here in Texas I would worry about the heat buildup for the setup. Though I can imagine you could put several holes in that deck, not impact the sound dampening too much, and mitigate that problem...

Then I also think you found a new storage area...

 

[Black Betty]

Then I also think you found a new storage area...
[/QUOTE]
Don't worry, it gets nice and warm in Queensland Australia too, I've left (read: 'not cut properly') some sizable gaps and am relying on the fresh air draw from the running engine to cool the space. As for the extra storage, I was initially exited at the prospect of being able to include a shallow basket to hold the wakeboarding vests but it turns out that the 'hood' has about 10-15mm clearance of the wood panneling. The only storage available is directly on the rear wall, where the newer AR's have cleverly installed a hinged hatch. I'm dead keen on Zippers' links for the exhaust wrapping as I have to get into that space to replace the deck drain fitting from the cursed plastic ont to the Stainless one.

 

[Scottintexas]

Then I also think you found a new storage area...

t
Don't worry, it gets nice and warm in Queensland Australia too,
[/QUOTE]


I was just about to ask you to post your location that maybe some of us could come by for a ride to see the difference, maybe in a few years when they lift the covid restrictions,

maybe take a video so we can hear it,

Also, if you haven't already, look at the thread in my signature about "known issues" for you boat model,


.

 

[Black Betty]

HA!, thought my location would be interesting. You're more than welcome to pop over when you can. We don't have many jet boats here, they're imported privately so we were very lucky to find ours. Always a great head turner, especially when we reverse to the bank of the dam and the crouds eagerly await for the prop to smash into the rocks! I'm very envious and keen to have a gander at others but don't get an oportunity. Though there was a recently imported 210 at the servo the other day, un modified. The guy loves them so we're keen to see how and what he modifies. I read your list over and over before buying the boat. I'm reasonably capable and keen to do work and repairs myself so none of the issues bothered me. Ran the YDS the other day, 158hrs on both engines! The fact that the engine and jet systems are so simple was a major selling point for me. Trouble and strife wanted a Tige or a Moomba but I also wanted a fishing boat, so this was the best of both worlds. Working on a ballast system currently.

 

[Farny]

Anyone ever used these products?

Boat Engine Compartment Insulation Guide - Second Skin Audio

The engine compartment is the loudest part of your boat. Fix the noise with engine compartment insulation material and simple boat soundproofing.

www.secondskinaudio.com