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Mercury outboard 150 seems excessively loud...

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andremike

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I just purchased a 2018 Bennington 23 RSB. It has the switchback rear seat design. I feel like the Mercury outboard 150 is very loud. It seems to run fine, has plenty of power, there is just alot of engine noise. What can i look for to diagnose this issue? does it seem noisy to me because the engine is right there? nothing to shield the noise due to the low seat design? Its particularly loud beyond mid-throttle.
 
I doubt that you have this feature, but you never know . On my 250 mercury, it has a selective exhaust setting. In 2014 I had a 150 mercury ,it did not have the selective exhaust setting.
 
I have a 200 Mercury Verado Pro. I know the Verado’s run quiet relative to their HP counterparts. But not sure on the non-Verado’s.
 
Our Mercury 150 is pretty quiet! I've gotten on it and asked my wife why she hasn't started it to warm it up and it was already on! It's also quiet underway. Don't know what to tell you!
 
My 2011 2 stroke 150hp Pro Xs was fairly quiet on our 2275 RCW and we could have conversations between me at the helm and the wife in the port passenger seat. Yours's is a 4 stroke which should be more quiet then my 2 stroke.

Motor height shouldn't matter. You have through hub exhaust. If your motor was mounted too high, you'd have performance issues with blow out in turns etc.

Not to be rude, but are you new to outboard motors? Just asking? If you are used to I/O's and inboards, they are much quieter then 2 stroke and even your newer 4 stoke outboard motors?

For an example, my twin engines on my Yamaha jet boat are so much quieter then my 2011 2275 RCW Bennington was with a 150HP 2 stroke Mercury Pro XS at idle and WOT.
 
No I am not new, I had another pontoon that had a 115 on it. But the pontoon had a different layout where tge motor was more covered by the interior


I had another thought.. if the exhaust is through the prop. Is it possible the motor is to high? I'll have to check the cavitation plate height. I thought when driving it, I didn't have alot of adjust ment on the trim before a blowout. It had to be pretty much down.

I am also wondering if it could be the prop that is on there.. I'll have to check, but I believe it's a stainless steel vengeance one
 
Can you tell if the noise is mostly exhaust or mechanical? Assuming you've checked the oil levels, it's possible to reduce mechanical noise with fresh oil in the motor AND lower unit. Use the best marine oil from Merc or Yamaha, no skimping. Use the highest viscosity allowed by the manufacture. If you are running regular gas, give mid-grade a try. Do you have the maintenance history of the motor? Could be something there tied to the noise too.

On a related issue, a friend has a Merc 150 on a CC that I think a bit loud, but our Yamaha 90 is pretty quiet...not a fair comparison.

How high is the motor mounted? Is the lower unit shaft length the correct one for your boat? Search for where the cavitation plate should be versus the motor pod/pontoons. Load distribution can effect when aeration occurs too.

Best of luck...
 
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Now that I think about it , I had a manifold gasket replaced on my Merc 150 .
 
If it is so loud you can't hear yourself talk then it is probably not do to furniture layout. Since you are not new to pontoon boats try to determine if it is combustion sound or other mechanical sounds.
 
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