1998 Formula Z 670. All stock except for a 1.25 inch ripsaw track unstudded, and went up a tooth on the bottom sprocket from stock 26/43 to 26/44. It engages smoothly right at factory spec 3,800, and the motor spins out to a perfect 7,900-ish top speed RPM on the tach at wot and gets to about 100mph on the speedo, so that's all good as far as I'm concerned. But that's the ONLY time this engine is running at peak HP.

I'm really trying to fully understand the exact purpose of secondary spring preload. Here's my situation:

Right now when I nail it from dead stop or slow speed, it winds only to about 7,000 rpm, drops to 6200 as it shifts out, and climbs back up to 7,900 as it accellerates to top speed. So only at 90 to 100 mph am I really in my powerband right now. So, if I increase my spring preload and change nothing else, could that theoretically change that sequence to: Punch it, spin up to 7,900, drop down to 7,100, and then accellerate back up to full speed from there? I would also assume increasing preload would increase my max speed RPM again, but I figure I can easily lower the clickers in the primary if that happens. If my thinking is correct, I can make the change and be closer to my powerband, but obviously still not a flat shift. But it'd be better than it was and won't cost me a penny. If I'm a nutcase and this won't work, please advise. I'd love to just try it and see what happens, but unfortunately we have no snow here right now, which obviously suks. So is my secondary preload thinking in this paragraph corrrect, or am I wrong?

Incidentally, clutch alignment and deflection is perfect, the belt is quite new and well within specs. So I'm sure it's inside the clutches. My gut tells me that a 2ndary preload increase will help cause the upshift to occur at a higher RPM. Am I wrong on this? I'd rather not spend the time/money on a clutch kit if I can just improve what I have in the short term.

Any thoughts from some clutching pros out there?