Custom exhaust for Zongshen engine - Question
 

I want to build a custom exhaust system for my 200cc Zongshen ATV engine. I started searching for the correct exhaust flange about and hour ago and have come up empty. The outlet on the engine appears to be for a 1.5" id / 1.625" od pipe secured by a two hole flange with bolts about 2-1/8" (58mm) apart. I'm very surprised that I can't find a flange with those dimensions. I'd appreciate guidance from anyone who can point me in the right direction.

Probably simplest to start with something close enough and massage things with a file or die grinder. These are pretty close and you get a pair to work with (for when your projects go like mine and things get messed up)
FORTLUFT Exhaust Flange Connection Kit (Mild Steel, 1.50''/38mm)

Alternatively, you could cut the existing flange off your current exhaust then clean it up and reuse?

Thanks for the quick reply. . . This project is from scratch so there is no old exhaust system. I could modify the part you referenced if needed. But I'm surprised that no one offers the correct flange given the number of these engines out there.

If you've got access to an angle grinder, bench vice, and drill press you can fab up a custom flange pretty quickly from a piece of flatbar (even Lowes mild steel would work).
Bolt holes can be drilled by hand but I find a drill press works better for running a hole saw to cut the inner hole.
I've made several 3" two bolt flanges for various Subaru Impreza projects over the years. Create a pattern out of thin cardboard (manila folder or cereal box) transfer that to the steel with a sharpie, then cut away.

I think I found what I want. Instead of searching by dimensions I searched for an old Honda flange. That yielded this finned flange of the correct dimensions.
https://i.ebayimg.com/images/g/lUgAA...xi/s-l1600.jpg

Those are typically used on pipes that have a lip on the end similar to this old CB750K pipe.
https://i.ebayimg.com/images/g/zYcAA...r/s-l1200.webp

Yeah, I may just buy a Honda CG125 exhaust pipe and work from there.