Lawn Mower Mufflers...
I post this, because as I was working on my exhaust for the past 2 days I found very little information regarding lawn mower mufflers and their compatibility with our Happy Fun Time Motors. Lawn mower mufflers alone are worth less.
I installed a "pancake" style muffler intended for 9-14 hp lawn mower/tractor. It was slightly less noise than just running a straight pipe, and my engine lacked "pep". Now the lack of "pep" might have been due to the long pipe in front of the muffler, but noise was my primary concern, and a large pancake muffler was almost useless. I do have plans to experiment with "stacking" mufflers, but I did not feel like throwing money at it this week.
I have since reconstructed my kit muffler and put that in front of the pancake muffler and my exhaust has a nice sound to it now, it chugs and pops more than whines.
Other side note which will not be news to most here, the pipe length before hitting your muffler makes a difference in performance, I am sure if you go to short that can be bad, but going to long is bad as well. Rudimentary pipe tuning is just finding the right length.
I have to post picture of my new exhaust, but I did build a weld free set up from about $20 dollars worth of parts from Lowes. I do realize I could have bought a new stock muffler for about that, but the project started off only costing $5 then $15 dollars later it worked...