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Intentionally plugged exhaust ports Alpha one

D

dhunt571

New member
"So my boat is a 91 searay wit

"So my boat is a 91 searay with a 3.0L alpha 1.
It is so SO LOUD anytime on plane... I've traced it back to the two exhaust ports being out of the water (So they dont muffle the sound.) What are your thoughts/experiences of plugging them up? Surely the prop exhaust is more than sufficient and it shouldnt choke the motor out... Does anyone know why the alpha one drive has these two exhaust ports next to the pivot point in the drive??? I don't think the old drives had these... I've already put insulation in the interior of the boat but when running down the lake, I can't hear my radio the exhaust is so noisy!!! What are your thoughts on plugging these ports??
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"Dude,... Fix your Post....

"Dude,... Fix your Post....

Whatever your Problem is,..
It Ain't the idle relief ports...
Plug them,+ it probably Won't start or run at idle..."
 
"and the ports have been there

"and the ports have been there along time, the 67 i had, had them, you can buy a wet muffler or a better radio and speakers. Best to get an amplifier and a good subwoofer.

ps.. what pitch is the 5 blade ??"
 
"My first guess would be to ch

"My first guess would be to check if the exhaust bellows is intact...

Also... if you run it on land with muffs, where does water come out?"
 
"It sounds like you're not

"It sounds like you're not getting sufficient water circulation. When these things work correctly there is adequate water mixed with the exhaust, that when it exits the leg, it should be barely perceptable. Bondo's right, the exhaust ports aren't your problem."
 
"The 5 blade is a 21 pitch.
H

"The 5 blade is a 21 pitch.
Hmmm. I'm getting plenty of cooling. When I run the boat with the "Muffs" out of the water, most of the water comes out of the starboard exhaust port, and a little out of the prop. Is this pretty normal?? for some reason the water favors the right side of the boat and not the left."
 
"who makes a muffler that wate

"who makes a muffler that water can run through? anyone have a link??? Also, will it physically fit in my 3.0 set up?"
 
"there is nothing wrong with a

"there is nothing wrong with anything you are questioning, it is all normal...........OK?

If your motor is too loud you can purchase some fire retardent foam for the inside of the motor cover. That will help some.

Overtons.com is a source for boat stuff
Westmarine.com

google it......."
 
""My first guess would be

""My first guess would be to check if the exhaust bellows is intact... "

i think that's a real good idea to start with (have you looked to see if the bellows are connected and intact)... something must be amiss for it to be too loud... if the exhaust is exiting through the prop like it's supposed to. it's always under water... muffled.. on the other hand. if the exhaust bellows is disconnected, while up on plane, it'd be open exhaust above the waterline..

as for where the water exits on the muffs. mine exits at both idle relief ports. starboard more than port in my case, why i don't know. also the pee hole at the ft. of the bullet on the lower (pees out a foot away from the drive, so a good stream) and through the prop. the water coming out the prop is more than a trickle. more like fast pouring a pitcher of water..."
 
 
"with the 5 blade and two peop

"with the 5 blade and two people in the boat. not much gear, and a full tank of gas, i run 51.6mph at 4600rpm and thats GPS. thats a top speed and the hole shot is pretty weak...
Now with a 17 pitch (what i use to ski with) top speed i run is 37mph and thats at 4900rpm. The motor will actually rev. to about 5200 but I dont run it at that...
The 17p is great for getting up and goin, but the 21 is a good cruise/speed.
With the 21p 5blade, I run average 43mph at 3900"
 
"anyone with a 3.0 running a m

"anyone with a 3.0 running a muffler in their system??? Anyone plug their ports up or thought about it? Also, whats the best soundproofing material out there? I've heard of the egg crate foam, dynamat, fatmat, etc... What works best?"
 
"There are two sources of nois

"There are two sources of noise.

Exhaust noise
Mechanical noise.

No muffler you can install is quiter than using the thru-the-prop system. Trust me on this.
If that system is workng properly, i.e., no holes in the bellows that's a quiet as its going to get.
Furthermore, installing a seperate muffler in most sterndrive boats is....challanging
and not inexpensive. I've been there and done that.

So the first thing you need to do is figure out
WHAT your problem is and not run around finding solutions.

Its a real easy test... When the boat is running
(with someone you can trust running it), go aft
and see where the noise is coming from.

You said that the water stream from the prop is "more like a trickle"... This would indicate
to me that either the exhaust bellows is defective, or there is a blockage in the exhaust system.

Now, so far as quieting mechanical noise from the engine... That can be difficult and expensive.
If the noise level bothers you on your power boat, do what I do when I want a quiet day
on the water listening to music... I go out on my 22 ft sail boat. On almost every power boat

I've ever been on, at cruise, conversation is "difficult". It's a boat...not a car...
power boats are...noisy. Unless you have an electric motor and are content
to go around at speeds under 5mph."
 
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