Exhaust flange insert

[GPracer2500]

85' ATC250R with a Paul Turner High Rev pipe. There is an insert inside the exhaust flange. It's not especially thick and is smooth with no discernable taper. It just slips into the flange before sliding the pipe on. It sits flush with the end of the flange.

Is this some sort of torque tube device? I've checked the fiche and it doesn't appear to be a stock piece.

[matt250r21]

It is not a stock part. LRD made those exhaust stuffers a while ago. I had one for MX, Cross Country. It was suppose to help lowed pulling power without hurting topend. I never felt a bit of difference. ESR also makes billet flanges with different inside diameters. The Sparks motor I just got, has a stock Honda exhaust flange that has been bored out 1mm. So theres lots of different ideas out there on how to make power in the exhaust flange.

[deathman53]

I had a motor with a thin metal sleave in the stock exhuast flange, I wondered what it was too. I threw that flange away, it leaked so bad.