Jetting a Rotax 670

[FoxDB 17]

I am installing a Rotax 670 in my Kitfox 1. It currently has the Arttic Sparrow Mixture control system installed that I was using on the 582. I would like to use it on the 670 but manuals say a different needle jet and needle are to be used. I could change the needle jet but it would be very difficult to change the needle as it is soldered in to allthread. Has anyone tried this and could advise me?

[Bandit 286]

I have been using the Artic Sparrow mixture control for years. Why couldn't you change main jets then turn your needle control full rich then lean it out until you get the right egt temps ?

[1avidflyer 1983]

I believe the main jet mostly controls the full throttle operation.  Perhaps you can go to a richer (larger sized) needle jet.  That and the jet needle give you mid range fuel mixture setting.  JImChuk