2006 Honda CH80 Elite scooter carb going on a GXH50.
Honda GXH50 carb port hole size is 15mm and the Elite CH80 4-stroke carb with a diaphragm port hole size is 18mm.
The 80 in CH80 stands for 80cc.
I purchased the OEM carb on ebay for $72 shipping included in great shape.
Test results should be ready in a week or two.
No porting is needed with the 18mm intake manifolds but a bunch of machining is needed for fit and attachment.
Intake manifolds from
http://www.motorparts4less.com/products.php?id=38 and I purchased two. Its a good thing I did because there's an uneven offset manifold holes to manifold port on one side but the other is even to the port meaning straight across the center of the port. Since the manifold only has one going across the center 2 are needed. This allows perfect match up after machining.
Throttle cable and handle from the CH80 are also needed for a professional attachment. Other throttle parts from motored bikes don't work. 1985 to current all CH80 cables handles and carb's are interchangable.