Found this while searching ebay for carb rebuild kits.
http://www.ebay.com/itm/Yamaha-XZ550-XZ-550-R-G-XZ550R-550R-Vision-Carburetor-Carb-Stage-1-3-Jet-Kit-/231425722030?pt=Motorcycles_Parts_Accessories&hash=item35e20c46ae&vxp=mtr (http://www.ebay.com/itm/Yamaha-XZ550-XZ-550-R-G-XZ550R-550R-Vision-Carburetor-Carb-Stage-1-3-Jet-Kit-/231425722030?pt=Motorcycles_Parts_Accessories&hash=item35e20c46ae&vxp=mtr)
Doesn't look like it has any gaskets or the other rebuild parts of the Kester kit. I wonder if it would be of use? I asked the seller what exaclty would be in this kit for a stock xz550.
I bought one and realized it was a mistake. They were real nice and returned my money plus shipping. They are apparently selling jets and support. BDC
Strange.but i can not find on Ebay anymore the kit i used.It was really great.It had all gaskets jets and everithing.And at begining when i did not know what year was me bike,i bought the wrong set,and they changed it just for shipping.
On the pfoto there was some girl,as i remember :) but i cannot find that seller anymore.It was 3 years ago,i guess.Btw it came with fuel pump set too
P.s. the package was like this http://www.popscreen.com/p/MTgyNTc3NjY5/Yamaha-XS400-Keyster-Carb-Kit-1977 I guess "Keyster" is the right name
I think I know the seller you are talking about, they sell a lot of Kester kits for other bikes. I can probably ask them to post a kit for sale.
Sirius on the web/eBay. Out of Canada. I just ordered and received the 83 Vision carb kit. Everything for both carbs and gaskets for the fuel pump. They show that they are out of the 82 kits at the moment.