I have recently purchased a used CSR 260 and while the overall performance is good the engine does not seem quite right. It seems to be running very rich and suffering hesitation in low to mid revs. I have looked through some old threads i can see stronger throttle return springs, roller barrel adjustment and ultimately ECU re-mapping as a resolution. I am looking for advice or a recommendation of a tuning shop in the Midlands who may be able to diagnose/resolve. Caterham seem very reluctant to touch the ECU??