Some of you seem to be confusing a tuned muffler with a tuned pipe? The Morris OSmod1 for OS46FX (and clones) to Rossi Round Mini-Tuned Pipe System is more in the area of being a tuned muffler. $49.95. It has a folded expansion chamber. It's folded back over itself. This might be to advantage to a lot of you? The original Tower 46 muffler costs only $13.99 and is almost as good.

Believe me, the Mac's one piece muffler is not tuned for anything. It's a very nice, quiet, light weight, muffler that doesn't fall apart, but tuned for anything it isn't. I have several and the one for a 46FX cuts the rpm down by 1,000 compared with using the original Tower 46 muffler. With the Mac's muffler the engine is real nice. Needle settings are very stable, there's no in flight quiting, the muffler doesn't fall apart, but the top end power isn't there.

Many more people run tuned mufflers than pipes. They are more realistic for the common man. Though even then, they are more effective at higher rpms than the lower ones. They do nothing to flatten torque curves or increase mid range torque.

By tuned mufflers, I mean things like a mouse' can or poor man's tuned muffler like the original Tower 46 muffler, or ones offered by other companies like Jett or Performance Specialties.

Pipes most often have more bragging rights than performance increase. I hope I havn't offended anyone who has already put out enough money for a pipe to buy another engine or a person who's already learned the truth and is trying to pass his off to some else.

The best way, I guess, is to prove it to yourself with accurate rpm checks and documentation of performance changes? Then you will know what you know and you will not listen to all the other claims. What's all important, is what works for you, even if it's just physiological?Enjoy,

Jim