Fog horn sound when underway from left side of pontoon boat

[Toonah]

Hi All, This site has been so helpful. Anyone ever have a sound coming from pontoons that sounds like a fog horn? It seems to come and go 1st I thought it was the wind passing through the alluminum or water on the pontoons but I only hear it on one side anyone know anything about this fog horn type sound? Thanks for any help.

 

[EGlideRider]

Re: Fog horn sound when underway from left side of pontoon boat

Just a wild guess here. My 4 stroke will make crazy sounds at certain RPM's caused by resonance of various boat parts. But nothing I would describe as a fog horn.

A slight change of RPM will cause that sound to stop but others may occur at different RPM's.

Try changing RPM's and report back here with as much information as possible.

 

[Toonah]

Re: Fog horn sound when underway from left side of pontoon boat

Yes I should have mentioned I do hear it at low trolling speed and at about 3000 rpm I don't however that maybe because I can't hear to much noise. It seems to only be on the non driver side which has the gas tank and I noticed full or even if not full of fuel. The speed thing is on the back of that toon, but I can't think that would do it. I just think it's odd that it would be on 1 side and not both. thx for any ideas

 

[EGlideRider]

Re: Fog horn sound when underway from left side of pontoon boat

If it does it at idle speed, that sort of illiminates a resonance caused by air or water so it makes my theory look a little better. Still a guess though.

 

[Toonah]

Re: Fog horn sound when underway from left side of pontoon boat

It does seem to make the sound at various speeds. So if it's from the engine can anything be done like putting a rubber pad between the engine mounting and the boat ... like the rubber pad on a small row boat engine? Thanks for the help.

 

[EGlideRider]

Re: Fog horn sound when underway from left side of pontoon boat

It does seem to make the sound at various speeds. So if it's from the engine can anything be done like putting a rubber pad between the engine mounting and the boat ... like the rubber pad on a small row boat engine? Thanks for the help.

My mechanic says he has tried the rubber shock mounts and obtained little improvement.

You might inspect the underside for loose nuts, parts, etc.

Good luck. And if you solve the problem, report back so that I might try your solution.

 

[Toonah]

Re: Fog horn sound when underway from left side of pontoon boat

Well we were having over charging issues with the last engine so now we have a Johnson 90 and I notice we still have the fog horn noise and I am thinking it has to do with some of the light scratches on that toon or engine vibration the gas tank is on that side and more of the seating so maybe the toon on that side sits a little lower in the water. All seems well as far as I can see and the boat is 93 so it's been around for quite sometime. Thanks all for your input.

 

[5150abf]

Re: Fog horn sound when underway from left side of pontoon boat

Get your fog horn going good and cut the engine, if the noise goes away you know where the culptrit is, as to what to do about it I don't have a clue.

Maybe have someon edrive the boat and see if you can pin point exactly where the noise is coming from.

I can't imagine what else it could be, built toons for a long time and never heard of such a thing.

 

[tygart river]

Re: Fog horn sound when underway from left side of pontoon boat

I have the same problem wit a 24 ft. pontoon with a metal top an a 28 hp johnson.At between 3000 an 3500 rpm it will drive you nuts.I have done about ever thing I can think of to no avail.The reason I was told what it was is harmonics. when everthing is at a certain sound pitch harmonics happen.B-S or not I have to agree.Buy at Iboats