Not strictly Sherco but related.   Is there any strip down or specification of the SPS Keihin carburettor on the internet?   I have a RTL that I've tried to fit a PWK Keihin that has an awful flat spot at about 1/3 throttle and won't start. I've tried many different jets and combinations, but it doesn't get much better. This sounds similar to the early Sherco 4T and was solved by the SPS Keihin carburettor. I can find the parts on Splat shop, but noting about how the parts are fitted.   I