I know the thread is about TBS needles, but I went with the Thruxton needles because they were easier to get than TBS's.
Also it would give me the difference in performance and fuel economy over stock needles.(I was running stock with one shim)
My ar$e dyno tells me I do have an increase in performance in the middle throttle range, but also an increase in fuel consumption. Whether my current fuel usage is below what is normally considered acceptable for these bikes I don't know.
My bike is a 2004 Speedmaster with a 790cc engine.
Setup is as my signature.
5.5 litres per 100 klms. 43 mpg US. 52 mpg Imp.
With stock needles and I shim.
5.1 litres per 100 klms. 46 mpg US. 55 mpg Imp.
I did the comparisons to give me the information and to also give them to Stacka who I know tried the Thruxton needles and wasn't impressed with the fuel consumption he was getting.
As far as I can tell from the information I have tried to glean from this site and other sites the 790cc engine with its different cams and Igniter (Ignition timing) performs completely differently than the 865cc engine with the same carb setup.
