Last year I was working on the exhaust for my old scooter and had trouble
getting the engine to rev up freely using two aftermarket mufflers for the
smaller Briggs Stratton engines (3-5 hp).
At the time, I didn't worry too much about it since the duals setup was in
development. I even put one muffler on my Snapper mower with no troubles.
The other one got lost somewhere.
The other day I was working on the exhaust again trying to set up a pair of
Harley style Fishtail exhaust tips and in my research, I opened up another
small muffler to see what was usable inside. And I discovered the
"advantage" of having trade agreements with China.
Inside the case was a short perforated tube held, in the middle, by a recess
in a baffle plate . . .except there were TWO plates instead if just one. I
checked the alignment of the plates by looking at the grinding marks from
the disassembly and the holes were not lined up. The restriction in the
muffler was probably 5 times higher than it should have been, if not more.
Now I suspect that is what happened on my exhaust previously, one
aftermarket muffler was assembled wrong and the back pressure went through
the roof because one small muffler couldn't flow enough under those
The warning is if anyone needs to replace a muffler on their lawnmower,
watch out for those made in China. If the engine runs worse, try another
Btw, I'm running dual, re-cased (1 3/4") large style (5-12 hp) mufflers now
and the pipes on the fishtail tips are long enough to give me a pair of
bologna sliced tips for everyday use.
"Our Constitution was made only for a moral and religious people.
Click to see the full signature.