Strange exhaust noise By mmcl26554 (Read 511 times)

[mmcl26554]

Peace racer 150.
Since mile "0" (now 850 miles) There has been a strange exhaust noise (a Buzzing sound) between 40-45 mph with light throttle. Noise goes away if I increase power or coast. I'm certain it is some kind of exhaust harmonic noise. Has anyone dealt with this and fixed it?

5/31/12 Update
I FOUND THE NOISE!
After playing with the exhaust and finding nothing I finally tried thumping on various parts of the scooter and muffler with a rubber hammer, suddenly when I hit on the right rear corner of the gas tank I heard a noise very similar to the one I had been hearing. A closer look revealed there is a rather thin cross bar under the gas tank, but about a 1/16 of a inch away from the tank. It would resonate when the exhaust sound matched the resonant frequency of the metal bar. I slid a plastic putty knife I had which fit firmly between the bar and gas tank. NO MORE NOISE. I always suspected something like this but couldn't find it. So if anyone else has a similar problem this is what to look for!
Michael

[alleyoop]

Check where it connects to the Motor the Flange you might have lost a nut or stud. Or they are loose. Now don't go and CRANK on it just nice and tight otherwise the STUDs will break. Or your muffler is leaking someplace and causeing vibrations.
Alleyoop

[blueboy5000]

It's rather common for these mufflers to become loose inside their aluminium covers simply from age and poor design.

It's so typical that we've begun calling it "gy6 vibrofarting". Usually you hear the greatest amount of farty buzzing at around 35 to 45 mph. It's not an actual problem per sey so long as your exhaust is tight, but it will cause annoying "farting "and will lead to future loosening of the flange, mounting and exhuast studs and bolts.

If your can has bolts holding the can to the pipe, throw some red loc-tite on those bad boys and torque 'em up. It may help.

To be honest, usually a new exhaust is the cure.

[tvnacman]

the baffel gets loose inside the muffler .
John