Yep,
The orig. Kymco metal U-shaped crush washer that was found residing in the cylinder head exhaust opening, after I removed the exhaust system, measures 30.34 x 23.00 x 3.45mm. (easily pulled it out with my finger)
The somewhat generic GY6 ex. gasket that I used upon exhaust re-install matched well when held together with the Kymco gasket. It measured 30.50 x 22.95 x 3.30mm. The pipe has a lip which fits into the gasket - it sealed well with the new GY6 gasket. Nice and quiet.
It is worth a periodic look at the exhaust system to stay ahead of any rust - as a replacement is $264.
Buy a new gasket, un-clip the 02 sensor, unbolt it and attend to things with some good high-temp paint**.
Any rusted bolts can be replaced cheaply from a fastenall type shop - and for $3.00 China will send you a kit of gasket, new studs and new long-bodied exhaust nuts. @$6.00 Stateside.
Stig
**A bonus is the new-scoot smell as you ride
- until the paint fully cures!