1978 250CR Jetting Question

I'm running the stock 38mm Mikuni on my 78 250CR and I'm looking for some jetting advice. I ran the bike with this jetting at Glen Helen (1,000ft Elev and 98F).

Needle: 6DH3 (one slot from the top)
Needle Jet: 166-Q8
Pilot: 45
Main Jet: 430

It seemed fat all around, but I sacrificed power for longevity (quite a few seizures that day).

I'm taking her to a race that will be 4,500ft Elevation and around 95F. I've moved the clip up to the top notch on the needle and gone to a 410 main jet as a start and will do a plug run after practice. Anyone have experience with the 38mm Mikuni at higher altitudes? Thanks for any help offered!

Jay

Race Report: The top end performance was good, but there weren't any long starightaways. It still felt a little rich bewteen 1/4 and 1/2 throttle (where i spent most of my time). Since the clip in in the top position I think maybe I need to carry another needle jet with me. Should I go to a Q6 or a Q4?

I see that one of the Husky Bulletins says to switch to the 166-R2 needle jet on the 1979 250CR. Aren't the motors the same on the 78-79 250CRs? I'm wondering if this would help my 78's jetting? I'm thinking maybe there are some differences otherwise they would have listed both years for the change. ???

ruwfo,

It was only 3/4 turn out. Could I have actually been lean at the 1/4 throttle?