Reducing Noise

[fortyplus]

I've recently returned from a trip with my Seagull 90 and an inflatable boat. For obvious reasons after running the motor for many hours my mind has been thinking about noise reduction modifications. I have an idea to calm the intake roar, but it will take a little time to find the necessary parts to rig a prototype of what I have in mind. Regarding exhaust noise, I've read here on the forum about diverting cooling water into the exhaust tube, and ways to block the "vent" holes in the tube. Are these really effective? I also saw a motor for sale on ebay where the seller is saying that stuffing the exhaust tube with stainless pan scourers is the way to go. So what does work to reduce noise significantly or do we just put up with it because it's part of the unique character?

[pat777]

I'm only new to seagulls myself so I can't vouch for any of these methods of noise reduction. Noise reduction is something I've been considering also. I came across a different seagull website before, with advice about reducing the noise level on a seagull outboard, it might give you some ideas (most of them are methods you have already mentioned), worth a look.

http://www.seagullparts.co.uk

http://www.seagullparts.co.uk/members/silence.html

Regards Pat

[chris]

If its to loud your to old.

[chris]

excuse last remark, reminds me of my parents telling me to turn down the radio because of that damn awful racket, now I am telling that to the younger ones.
My father used to say "they sound really good until they open their mouth"

With my boat the seagull 40+ bing carb is on the port transom as far to the side as I can get it and is fixed, I steer with the tiller and sit about the middle of the boat which means the noise is not so bad, I spent 11 hours sitting next to my silver century once with my old boat, not very pleasant, I think filling the exhaust tube up with that stuff might affect the running, The 102's are a lot quieter but are a bit to heavy for my boat,

[fortyplus]

Thanks for the replies, perhaps if I were really old, I'd be deaf enough not to hear the noise - while the noise does bother me, I think it bothers others more, so there is an embarrassment factor. I think using the stainless pan scourers would work really well to reduce noise, I used some to quieten a motorcycle exhaust once and they worked very well and were open enough to not restrict gas flow - however in a Seagull I forsee problems with them getting sludged up quickly with oil due to the low exhaust temperatures whereas in a road going application the oil will burn off.

[pat777]

I think using the stainless pan scourers would work really well to reduce noise, I used some to quieten a motorcycle exhaust once and they worked very well and were open enough to not restrict gas flow - however in a Seagull I forsee problems with them getting sludged up quickly with oil due to the low exhaust temperatures whereas in a road going application the oil will burn off.

I'd say it's a method worth trying out all right, keep us posted on how it works out for you. I think we need some boffins with a noise meter to do some experiments with all these ideas.

As far as the low exhaust temperatures, my elbow certainly didn't think the temperature of the exhaust was that low when I accidentally tipped off it when I was unclogging weed from the propeller. I won't be doing that again I assure you. I guess the pan scourers will need regular replacing/cleaning. Is it a big/time consuming job getting the exhaust off a seagull?

Cheers Pat

[fortyplus]

I think getting it apart to do it is not a big job in itself, until like many "simple" tasks, you hit the fastener that does want to come undone or some other seized part. I agree the part of the exhaust above the waterline can get hot enough to be unpleasant to the touch but the end in the water is always cool, if I were to do it, I'd first try putting some packing above the water line as far down from the exhaust port as possible, it may not need much length of packing to make a big difference.

As you say we need to find someone with a lot of spare time and a noise meter to document the noise reduction and any possible power loss achieved by the various measures - any volunteers?

[RickUK]

If noise is an issue for you, it will never be resolved whatever you do to a Seagull - you might get to what you consider acceptable limits with a very late Seagull such as a Curlew, but otherwise a small Japanese engine would be better for you, which is probably better on an inflatable anyway.

[Niander101]

I had a little yamaha 2 but sold it...nice motor but very boring!

[fortyplus]

If noise is an issue for you, it will never be resolved whatever you do to a Seagull - you might get to what you consider acceptable limits with a very late Seagull such as a Curlew, but otherwise a small Japanese engine would be better for you, which is probably better on an inflatable anyway.

Yes I'm trying to resist the lure of a newer 6-10 hp unit that would really make the inflatable come into it's own, however I was still pleasantly surprised by how the 90 handled the task and it's always cheaper to use a good reliable motor you already own. I didn't find the noise too bad if I could just take a little off the overall bark I could live with that. There is something satisfying about defying the odds and convention with a motor with such an individual character, a modern 4 stroke would seem very dull and not have the nostalgic connection to my youth.

Does running the cooling water through the exhaust tube make a worthwhile difference, cleaning up my motor today, I found the extended use had left a stain/deposit of calcium and rust on the exhaust tube where the stream of cooling water hits, that I could only remove with Muriatic acid - so this mod could cure two birds with one stone, perhaps three if it helps flush some of the "oil jollop" out of the exhaust while running. Why did Seagull stop the practice of doing this after the 102 model, was there some downside?

[1650bullet]

I seem to think if you start modifying exhausts on a seagull, Your going to run into dramas, Playing around with such thing will take the character and nostalgia out of your seagull, Just leave it go and enjoy all of that wonderful noise and smoke that they so lovingly produce.

[woodbutchergraham]

quote="RickUK"]If noise is an issue for you, it will never be resolved whatever you do to a Seagull - you might get to what you consider acceptable limits with a very late Seagull such as a Curlew, but otherwise a small Japanese engine would be better for you, which is probably better on an inflatable anyway.[/quote]

Although I have to agree with Rick regarding inflatables and Seagulls it never stops me!
[attachment=0]IMG_0106.JPG[/attachment][
The first run out with my SD im pleased with both its performance and its looks and the noise is what Seagulls are all about as well as that smell

[Niander101]

Very nice but please turn it the right way up
my eyes are going funny

[woodbutchergraham]

A short trip but it was good to be back on the water

[chris]

part of owning a seagull is the mosquito eradication, the industrial deafness, the oil slick, you don't get these pleasures with modern outboards