Briggs 5hp Exhaust Mod

[Apollo HT]

I have read about people installing pipe, onto the muffler outlet, and routing the pipe down to the cavitation plate. So the exhaust exits underwater, resulting in a much quieter outboard.

There is also mention of drilling a small hole in the pipe, above the waterline, so the engine does not suck the water up the pipe.

Does anyone have any pictures, drawings, or experience with making this modification?

Thanks

 

[Coal]

Yes I did see where someone brazed copper tubing to the muffler. The person stated stated that it worked well. I don't recall if he drilled a small hole above the waterline.

 

[F_R]

Have no experience with a B&S outboard, but plenty of experience with outboards in general. So, yes I would say that an above water exhaust relief hole is necessary. Even if for no other reason than to relieve back pressure for easier starting and good idle. Also, your installation should direct the underwater exhaust rearward, aft of the prop.

 

[gm280]

Sure makes perfect sense to me to have a relief hole above the waterline to keep water from back tacking into the cylinder. :noidea;