KLS and Battle Factory. I use both on RS125s (A & B bikes) - spend the extra money for the KLS. When the BF goes, you're done. If the KLS fails, you're still running fine, but no quick shift. The KLS is also easier to adjust relative to your shifter in terms of foot pressure sensitivity.
Thanks Brooklyn67 The KLS looks about right, I also was directed to a chap in Ireland makes a kit much like the KLS and will be receiving a unit to test this on RS125 so will report back. Do you use duct tape to control engine temps or a thermostatic bypass? ....I just hijacked my own thread.
I'm curious to hear about the other quick shifter, how much is it? I assume it's cheaper than the KLS. Water temp: I've always used tape - vertical strips, instead of taping across the radiator. I also leave the top end of tape long - sticking the end tacked to the top of the frame or the bottom/front of the fuel tank on the left side - so I can rip off this strip with my left hand in a race if (for some reason) water temps rise. An old teammate used a valve spliced into right side radiator hose. He didn't use tape and would turn the valve at speed in a race to increase/decrease the flow to keep temps between 52-56 degrees. Worked for him, but I couldn't imagine turning/adjusting that little valve, with my gloves on...in a race, especially if you're battling. If you know your bike, you'll always know how much tape it will need.
@DonTZ125 sells a quickshifter kit that will likely work. He's Canadian (don't hold it against him) and might have some stuff ready to ship. Decent price and nicely packaged.
I have had Battle Factory stuff on both 125's and my 250 with zero issues in 15+ years. Stewart over at Rising Sun Cycles is who I have dealt with recently on parts and he does have them in stock I believe. Think I saw he had the thermostat systems as well, I have never used one though, like Brooklyn67 said, once you get to know your bike you know how much tape it needs. Keep your log book sorted.