pipe size?

[wiredgeorge_imp]

Sorry, I guess I didn't read the request close enough.

Using a micrometer, I read 1.667 inches. Hope that helps.
I forgot our bike is metric.

In MM it read 42.59 in one place, a little less in another.
And to add, the muffler has never been installed on a bike.

Harley, Yamaha, Kawasaki, BMW use 1 7/8" ID mufflers. I was hoping that would be the measurement so I could use a generic muffler on my bike. The OD of the head pipe on most is 1 3/4". The muffler manufacturer will sometimes give you a shim to use the muffler on a 1 1/2" OD headpipe so one may work. Anyway, thanks! wg