Wet Exhaust Mufflers

[The Dog House]

The wet exhaust mufflers on my Trojan F26 were installed in 2002. During a long trip this past weekend the boat seemed very loud. Do wet exhaust mufflers wear out or are these boats just naturally loud? Thanks for any insight you can provide.

[Paul]

I have a single Vernatone on mine and it all fiberglass with a fixed baffle in it, nothing that will wear out. You might want to inspect your muffler mounts to be sure that everything is tight, vibration from the muffler resonating thru a loose hanger can get pretty noisy.

Originally, mine was hung from the underside of the cockpit floor with stainless steel hangers which transferred allot of noise and vibration into the cockpit. To eliminate this, I made a wood cradle and epoxied it to the hull, then lined it with soft rubber and placed the muffler in. Cockpit became much quieter.

[The Dog House]

I have a single Vernatone on mine and it all fiberglass with a fixed baffle in it, nothing that will wear out. You might want to inspect your muffler mounts to be sure that everything is tight, vibration from the muffler resonating thru a loose hanger can get pretty noisy.

Originally, mine was hung from the underside of the cockpit floor with stainless steel hangers which transferred allot of noise and vibration into the cockpit. To eliminate this, I made a wood cradle and epoxied it to the hull, then lined it with soft rubber and placed the muffler in. Cockpit became much quieter.

Thanks for the insight. I have two Vernatone mufflers that are hung from the underside of the cockpit floor with stainless steel hangers. I'll put my thinking cap on and see what I can do to minimize the vibration transfer.

[vabeach1234]

You may want to check to see if you are pumping enough water. The water in a wet exhaust system helps muffle the sound. When my impeller locked up (i.e. no water); the exhaust note instantly changed. Was the engine temp in normal range?

Just something to consider.

[The Dog House]

You may want to check to see if you are pumping enough water. The water in a wet exhaust system helps muffle the sound. When my impeller locked up (i.e. no water); the exhaust note instantly changed. Was the engine temp in normal range?

Just something to consider.

I replaced my impellers at the beginning of this season. My engine temperature is normal and I have a waterfall coming out of the exhaust pipes when on plane at 3000 rpm. I definitely have enough water flowing. It may be that having two exhaust pipes sticking out above the water is going to be loud no matter what I do. I may not be a "go fast", but I certainly sound like one.

[prowlersfish]

Low water flow can burn out the baffles inside .

[The Dog House]

Low water flow can burn out the baffles inside .

Is there any way to tell if the baffles have been burned out? I'm willing to purchase new mufflers if they will reduce the noise levels, but I don't want to spend the money for no improvement.

[prowlersfish]

Just pulling them and looking . Converting to single exhaust would reduce the noise level .

[Paul]

Low water flow can burn out the baffles inside .

Is there any way to tell if the baffles have been burned out? I'm willing to purchase new mufflers if they will reduce the noise levels, but I don't want to spend the money for no improvement.

I made a boot for my exhaust that mounts over the exhaust tip and re-directs it below the bottom of the hull, this keeps things as quiet as possible. I love the sound of a finely tuned engine but not for hours uninterrupted. With this boot, i can actually hear my VHF radio while under way.

Although I made my own, there's a company called Salisbury that sells them.

Hope this helps,

[rickalan35]

Paul, I have a question. I used to own an old Shepherd cruiser back in the day that had a pair 331 Chrysler hemi's for power. When I bought her, she already had four 4" heater tubes extending from the four exhausts into the water for noise reduction. They worked great.

One day a guy came along who told me that if the engines backfired or dieseled, they would turn the crank backwards and suck water into the engines. I didn't know whether to believe him or not. But I removed the tubes.

I don't think a 4 stroke engine can rotate in the wrong direction for any of the above reasons. But since the topic of tubes on the exhausts has been raised, can anyone comment on this rotating backward point?? Thanks.

[prowlersfish]

Wrong Paul but I will answer the question It could happen , that's one reason most under water exhust have a relief port above the water line . I believe the Salisbury units have it

[vabeach1234]

I'd love to find where to buy these Salisbury Units. I couldn't find any suppliers online.

[Cmount]

On my f32, I had a noisy engine exhaust...replaced the muffler and no improvement. What I actually determines was there was not enough water in the baffles, due to a decrease in water flow. The engine always steamed, but it never got overly hot...and once I got the water flow corrected, the exhaust quieted right down. It was in the heat exchanger and oil cooler...cleaned them up a bit, a little salt away, and poof...all good.

Former f32 owner