I think you are correct regarding ZAMA carbs being unique for STIHL. However, ZAMA carbs that are STIHIL-unique can be found through other channels. Typical STIHL parts must be bought through STIHL channels, but carbs must get a reprieve from that requirement. For example, my FS90 uses a C1Q-S72 carb. Here is a link to buy one off e-bay, http://www.ebay.com/itm/CARBURETOR-...A%2BFICS%2BUFI&otn=21&pmod=350669852108&ps=54 I don't think I can buy any other STIHL part from a different channel. This e-bay link is only an example. There are many other places that make a C1Q-S72 available, full carb, not just the RB-97 rebuild kit. Strange business ... BTW, I would agree with others here -- better to buy a new carb than do the rebuild. I did not take this advice earlier, and rebuilt several. Hindsight tells me better to buy a replacement carb.