Zong owners are very fortunate that the Sierra 200GY-2 is such a close copy of the currently produced, Yamaha TW200 motorcycle.
Since the TW200 has been in continuous production since 1986, we will never need to worry about securing replacement parts for our Zongshen 167FML engines.
In addition, we also have access to the excellent TW200 Service Manual available for repairing, and maintaining our motorcycles. We are also very fortunate to have access to the superb information available from Yamaha owners who contribute to the TW200 forum.
http://tw200forum.com/forums/
The TK MV28 carburetors installed on our Zongshen motorcycles are slightly different from the TK MV28 carburetors installed on the Yamaha TW200. However, most of these minor differences work in our favor!
The Yamaha carburetor employs two throttle cables, located on the right side of the carburetor; the Zongshen carburetor employs one throttle cable, and a return spring, located on the left side of the carburetor.
The Yamaha carburetor jet needle is not notched for height adjustment; the Zongshen carburetor jet needle
is notched.
The Yamaha carburetor has a choke knob located on the carburetor body; the Zongshen carburetor has a remote choke adjustment, located on the left handlebar.
The TW200 pilot mixture screw is hidden under a brass cap, on the bottom of the carburetor; the Zongshen pilot mixture screw is easily accessible on the left side of the carburetor.
Despite these minor differences, the two TK MV28 carburetors are essentially the same. Therefore, I have provided a few links to TK MV28 carburetor threads located on the Yamaha TW200 forum. The first link, authored by Centerline, provides excellent photographs, and a detailed description of adjusting the TK MV28 carburetor jet needle, and main fuel jet.
http://tw200forum.com/forums/1/28976...ost.aspx#28976
The next link provides a lot of good, general information concerning TK MV28 carburetor removal, rotation, and cleaning.
http://tw200forum.com/forums/71353/ShowPost.aspx
Also, if you are interested in TK MV28 carburetor jet information regarding the Zongshen Sierra 200GY-2, you might enjoy reading the following thread, posted here, at China Riders.
http://chinariders.net/modules.php?n...ewtopic&t=9165
Spud