- Prather
Muffler Mod
- by Don Mock
- I understand the struggle to find a
muffler combination that is quiet without significant power loss.
If you are running a Picco, like nearly 90% of the club, it's
not difficult to keep the awesome horsepower and run around 85dbs.
Most have also found that the Steve Muck pipe offers the best
results. So,the trick to a quiet setup with a Picco with a Muck
pipe is some kind of baffled muffler.
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- In desperation last year, after the
airplane mufflers I was using fell apart, I sawed a stock 11cc
Prather muffler in half and added a baffle and had it welded
back together. It worked very well.
-
- Here's how. After cross-cutting the
muffler, I cut a round disk out of 1/8" aluminum the size
of the interior diameter of the muffler. There is a tube that
runs through the muffler that I needed to trim down (on only
one of the halves) 1/8" to allow the disk to seat flush
into the muffler half. I drilled four 1/4" holes, equally
spaced, in the disk about an 1/8" from the outer edge. Then
placed the disk back into the muffler half and headed to the
welder's shop. Once welded, the disk stays in place (held by
the two facing tubes and probably a bit of the weld too).
-
- When I first tested the muffler the
boat was incredibly quiet, too quiet as far as I was concerned.
I couldn't hear the engine very well on the launch and while
running to get a feel for the tune-up. So I drilled a 1/4"
hole in the center of the baffle (using a long drill bit). This
only made the boat slightly louder and increased the engines
performance. I've come to the conclusion that one of the reasons
this modification works so well is that the solid baffle, along
with the weld, not only re-routes the sound waves but also deadens
the loud "rattle" heard with stock Prather mufflers.
-
- Total cost for this muffler ended up
being around $35 including the welding.
- .