I seem to recall that the K3 pull cable is far longer than the CB500/550 ones due to the PD carbs and the position of the butterfly. I'm looking to see if my memory is correct, I need to know after all the cable is pulled out at the bottom (carb end) how much inner cable is showing, I can then compare that with the standard cable and see what if any the difference is.
If you've got the push cable handy same measurement would be great thanks.
I'm trying to reduce the amount of throttle movement is required and this will help me work out the mod, one mod is at the handlebar end and one at the carb end, unfortunately the carb end ones won't work on the K3, well not unless you can adapt it but the handlebar end is ok for all the SOHC fours are far as I know. Once it's done I'll pass on the details, the handlebar one already works and reduces full opening by 8-10mm. It's a fairly cheap mod (around £10-15) and requires no real mechanical ability.
