Exhaust leak

[coleman66six]

Basically one of my pipes where the silencer meets, the rubber piece that seals it ripped in half. I noticed a big loss of power in the top end. So I tried to rig it for the rest of the ride and it kinda worked for a little and I felt the power come back. Anyway, now I have new ones I just bought that look and feel way nicer and have better clamps. My question was, does a exhaust leak really cause this much loss in power??? Is this due to the acoustic waves in the pipe escaping and not bouncing back to give back pressure and push any escaped fuel back in??

[AKheathen]

long story short: i did the same thing on one of my first rides.   wrapped the joint with mcdanalds nugget box and kept going for a while.   the expansion chamber works like a turbo.  among the differences, is that it uses the restriction shape and timing to send the exhast pulse back to the exhaust port at a certain time.  if the port is still open, it stuffs the cylinder with more pressure.   the time is related to rpm, and thats why they work better at certain rpm ranges.  the restriction of the "stinger" and its own time value has an effect on how strong the pulse reflects back to the port to stuff the cylinder with more pressure.   having a leak right at the back of the chamber lowers the pressure of the spike back.   the distance also lowers the pressure, or raises it, depending.