Re: Please Help
I had issues with the muffler too.
First thing I did with my muffler is removed the gasket, took a wire brush to it and then applied some high temp gasket maker to the current gasket, on both sides. Put that back on, then I installed the muffler, using 2 lock washers for each bolt, then BLUE loctite. If you use the red, it'll never come off.
As for the sputtering and reving up, it's because the muffler isn't there. An engine won't run properly without the proper muffler installed. When my gasket went, the engine would sputter and rev up too, now that i've fixed that it's fine, and actually quieter than ever!
For the fuel, you should run 32:1, you can check a conversion chart. Most pocket bikes/2 stroke bikes run at that mixture, it's a good balance.