Small engine muffler- extra parts?

CobyRupert · May 9, 2020

I ordered a new muffler for my mom’s 1970 Montgomery Ward’s rototiller. It’s has a small single cylinder Briggs and Stratton motor on it. New muffler came with “extra parts”. That is, the existing muffler doesn’t have a “deflector” that screws on to the exhaust port like the new muffler. 2 styles of deflector came with the new muffler.
Should I use one?
Will one style make it more quieter than the other?
Will one cause more back pressure and rob power vs. other?

Hopefully these “deflectors” make a decibal reduction as I don’t think the old muffler is too bad, just missing a deflector.
What say you?

Diggin It · May 9, 2020

Spark arrester?

flyerdan · May 9, 2020

It looks like a universal type, and the deflector would be for keeping the exhaust from blowing on you if the muffler faced you. I doubt very much if it will make any difference if you use it or not, performance wise. If you can point it downward it will likely reduce the noise a bit.

CobyRupert · May 9, 2020

Arrestor? She didn’t even do anything wrong!
I’m looking more for a officer of the peace (and quite).

It’s a 4 cycle. Fire is not a concern.
Well....I say that, but I did also ordered a new gas cap, the safety police would be shocked if they saw how much raw gas would splash out the cap’s vent holes and literally run across surfaces inches from the muffler.
I’m surprised it never burst into flames in the garden. I was always ready to shovel dirt on it to put it out.....but I’d probably just keep shoveling and bury the old gal right there for good.

I guess my question is: What’s the pro/cons of the two different styles?

CobyRupert · May 9, 2020

flyerdan said:
It looks like a universal type, and the deflector would be for keeping the exhaust from blowing on you if the muffler faced you. I doubt very much if it will make any difference if you use it or not, performance wise. If you can point it downward it will likely reduce the noise a bit.

So the “90 deg” one is probably quieter than the “straight through” one?

flyerdan · May 9, 2020

It should be; it can be mounted in four directions so the exhaust can be directed down, up, forward or backward so you should be able to get a configuration where it isn't blowing in your face when using it. Either downward or forward should be best for lowering nose level for the operator.
The round one has the potential that you can weld a sweep on it at say 4:30 so it will direct the exhaust down and a bit forward (or backward depending on which side). Looks like a chunk on 1.375" fence tubing would work, cut a section out of an old bent frame corner.

CobyRupert · May 9, 2020

flyerdan said:
......The round one has the potential that you can weld a sweep on it at say 4:30 so it will direct the exhaust down and a bit forward (or backward depending on which side). Looks like a chunk on 1.375" fence tubing would work, cut a section out of an old bent frame corner.

Ahh. That makes sense. Thanks.

Perhaps for a chrome straight pipe stack? I hear that will give it 5 extra hp.
For now, I’ll throw it in the extra part bin of things I might use someday. I’m now at the age when that bin is also the ‘I’ve never used it and don’t remember what it’s for, throw it away’ bin.

flyerdan · May 9, 2020

I'm right up there in the save it for later use category. Just a little while ago I pulled down some very nice original seat covers for a 75 Corolla from the shop attic. They've been up there for almost thirty years, the cars are long since gone. Listed them on craigslist free section in case someone is needing some for a restoration.
If you're plagued with gophers, you could weld a pipe coupler on that flange, and get a piece of flex pipe to bury in the gopher hole. My dad did that after those "Gopher Gassers" came out back in the early 70's, kind of a mini cyanide road flare that you'd torch off and bury in the hole. Since gas was so cheap back then we used it for parts washing, it was way less expensive than the tailor-mades.