Your OEM TMXx is a far superior carb than either the TMX or TMS. The TMS is the latest version of the TM series. First we had the TM with many of the VM or round slide adjustments including the changeable jet needle (brass emulsifying tube). The TMX was next but a bit thinner, plastic inlet needle and a non-removable jet needle. The TMS has taken that one step further buy removing a few more jets. I have seen a few guys make the TMS work – but I can’t see anything good myself. Take a good look at your Japan or OEM TMXx and then look at a standard Mikuni TMX and you will see what I mean. Bob Hogg :cool: