Are Suzuki 50 HP Motors Unusually Loud?

Blueback · Posted: Fri Jun 16, 2006 8:41 pm Post subject:

Hi all,
This is a fasinating subject for me as I have felt very alone with my quest to stop, or reduce, the outboard noise at source. I have a yamie 2 stroke that got into my head like a dentist drill. The dealer implied that I was too old for high frequentcy noise. So I took off the cowling and lead lined it and then added a cork lining. Yes it was better but not good enough for me. Part of the noise is hull transmission and the cabin amplifies it. I was going to sell the 2 stroke and buy a four stroke yamie--and now I read this thread !!!! wow --what it the answer.

thataway · Posted: Sat Jun 17, 2006 2:06 pm Post subject:

I have found the mylar/foam/vinyl/lead/foam/mylar laminate is better than others- If you can add in a layer of 3/4" plywood--it will really quiet it down.....but the plywood is a problem! :D

dogon dory · Posted: Sat Jun 17, 2006 4:56 pm Post subject:

Sorry, Folks - Post Deleted By Author

Blueback · Posted: Sat Jun 17, 2006 10:00 pm Post subject: Foam Ear syndrome

Foam ear plugs ---eh-- what did you say-- form ear lugs. Ok you don’t have to shout just throttle back that damn engine I didn’t hear you.
But we will have a great conversation when we arrive and pull the plugs won't we.

Blueback · Posted: Sun Jun 18, 2006 2:50 am Post subject:

Has anyone used a db meter to take a reading in the cabin of a 16' C-Dory. My guess is it's about 80-85 dbs at WOT and if thats right, see below for a scale and the expected result.
My goal would be to see a noise level of no more than 70dbs. Remember dbs is a log scale to the power of 10--although our ears are not running on the suggested intensity of the log scale-- we seem to adjust.

85 dbs
Upper limit for any comfort, which is limited. Ear muffs suggested for log exposure

80
1 meter from ringing alarm clock. Conversation is difficult. After a 1-hour exposure, thought is difficult and the stomach contracts.

75
Railroad carriage. Normal conversation not possible. Consensus of experts is that sound levels below 75 dBA "are unlikely to cause permanent hearing damage."

70
Small car at 30 mph; 3 meters from a vacuum cleaner.

dogon dory · Posted: Sun Jun 18, 2006 3:39 am Post subject:

Sorry, Folks - Post Deleted By Author

Sea Wolf · Posted: Sun Jun 18, 2006 10:59 am Post subject:

From a technical point of view, the multi-layered approach mentioned by Thataaway is interesting. Sounds like something developed to enclose equipment on a submarine! Bob- do you know anything about the history of the development of this technology?

Does the same noise problem exist in the 18, 19, and open bulkhead 22 Sport Cruiser? Could be there's something specific about the resonant frerquency of the 16's cabin size and engine rpm matchup?

I still think earplugs may win the economic side of the war!

In desparation, one could always invite Byrdman along with his 8-track player and tape of Iron Butterfly's Inagaddavida played at 10 or more db over the engine noise!

Joe.

Robbi · Posted: Sun Jun 18, 2006 12:11 pm Post subject:

This is a great discussion.

The noise level in the cabin of my 19 is not uncomfortable for me. But, it is uncomfortable for my husband. Irony; he has some hearing loss. I would love to get a db reading in the cockpit, with the drop curtain in place and without. The curtain does dampen the level of noise. I think that you can rent a db meter, I am going to look into that. I would recommend to anyone who notices the noise "more this year than last", and "head ringing" that has not been experienced before, to check out the engine, and to get your hearing checked. I am sure that someone out there knows much more about the many types of hearing loss, tinnitus, etc. than I do. I do know that one type of hearing loss can cause discomfort around certain noise frequencies. A bit counter intuitive.

As far as quieting an engine, would a plexiglass or lexan deflector mounted in front of the engine, canted towards the stern, deflect some of the noise? Or maybe just go fast enough to leave the noise behind? Zoom Zoom.

I am off to catch a crab! Robbi

DaveS · Posted: Mon Jun 19, 2006 12:59 am Post subject:

Blueback · Posted: Mon Jun 19, 2006 1:09 am Post subject:

Hey Robbi that zoom--zoom is petty funny alright as Mach I is about 700 MPH and thats when your move faster than your sound.

Byrdman · Posted: Mon Jun 19, 2006 10:11 am Post subject:

No to answer your post question.... The 50 hp Suzi is not a "loud" motor. You go sit in the pews of some old churches... Yep, that cathedral shaped alter area is that way for a reason.....to bounce the sound "AT" the congregation.... In a 16...and even the 19.... YOU ARE THE CONGREGATION... Robbie is right on target. It is really wild how little it takes to "bounce the sound" in another direction. Go to HomeDepot, buy a roll of duct tape, and a piece of that insulation board in 4x8' sheets. And.. get some goo stuff to remove the tape gunk when you finish this test... Now, simply cut a 4 sided box shape with a box cutter razor blade to fit the shape you need.... forward edge, two sides... and the top piece....leaving the aft facing side open to allow the sound to "bounce" aft of the boat. Duct tape it to your hull... This is a proto-type design...that you can try for less than $20 to see if it works... if it does... Then simply cover the "box" in some 1/4" AC plywood.... after you paint it up good to match the paint design of your boat and...to keep the water out of the wood...and you can trim it all up nice and pretty with some type of trim strips... CoolSmile

and go ahead and enjoy a conversation on your boat.

Norm S · Posted: Mon Jun 19, 2006 10:46 am Post subject:

On my buddys' little Arima we built a removable hinged table that goes over the motor well out of starboard. Sorry I don't have a picture handy but it is similar to the one the Arima factory sells for their boats. It does seem to block a lot of the noise. Also provides some nice usable space that is otherwise wasted.
Norm

Byrdman · Posted: Mon Jun 19, 2006 11:03 am Post subject:

Opps.... upon re-read..... I forgot our 18 anglers (all 14 of them)... have the same effect. Norm... I will have to take a look at their site...

Norm.. I should go pick up C-Byrd this week...going with a jackplate of 10 or 12"... so.... I need to get my thoughts going a bit on the aft section of her.... and this sounds good....no pun intended.

Byrdman

Norm S · Posted: Mon Jun 19, 2006 11:17 am Post subject:

No Patrick, Mine does not have that effect. Remember mine has the bulkhead and door like her big sisters. Definitely the way to go IMHO.
Norm