Guys, I know that a lot of you run the ys four strokes with the tuned pipe with the tuned pipe.
I really would like to know if this is a good match. I have been told that this setu p causes lots of engine problems, even lots of breakage of engine parts. The reason I am so curious is that years ago I purchased the pipe and engines but never used them, I would like to use the pipe on my ys120 sc the motor runs great with a little standard muffler but very loud and I think the pipe might help with that. I don't need ant extra power just want to use the pipe.
Is the setup different with the pipe.

Please give me any knowledge that may help on this.
Thanks in advance
Jeff

The benefit of the tuned pipe on a 4-stroke is not the exhaust tuning effect, which basically does not apply to a 4-stroke; the benefit is a cleaner looking installation, less drag than a muffler sticking out into the airstream, and sometimes a larger volume will let you pick up a couple hundred rpm. Breakage problems are typically from poor pipe and header mounting, not allowing for vibration, resulting in lots of broken headers. I've not heard of much in the way of actual engine parts breakage. Use a Dave Brown mount, or other soft mounting device on the pipe. If the header is long and rigid, it helps to brace it to a fixed spot on the engine (but make sure the pipe is free to follow the vibrating header. Pretty much any old .40 size pipe will do just fine. The old Johnson flexible headers work great, as do the new short NMP headers from Central Hobbies. Also, you may find that a YS that sounds loud on the bench or in the pits will sound very mellow and inoffensive in the air. If your YS is hard-mounted, header life will be better but airframe and servos will suffer more.