I have this muffler on a Saito 180 mounted in a H9 quarter scale Cap (The blue and white one). It had the stock muffler in it originally. I love it. It's seems slightly quieter than the stock muffler. Also, I have not had any fuel flow problems, seems to provide plenty of back pressure. I have the smoke version, but have not yet run smoke through it.

I did have to cut a notch out of the cowl to accomodate the can part of the muffler. The Cap cowl easily accomodated the Saito on its side, but the cowl narrows below the cylinder head location and that's where this muffler sticks out.

Jason