had a huge tuning problem recently, tried everything, disconnected kill switch, new coil, swapped stators, checked everything 3 new b7es plugs, screwed with jetting, tossed intelajet and went with roostys baseline, removed nology wire and swapped for a solid core wire with a 0 ohm cap.......
bike wouldnt run right on the low end and would take a bit to clean out on top, jetting changes didnt have much effect, also when it got real hot (240f+)it would just shut off at low rpms for no reason without warning
it basicaly ran terrible
it ended up being the digital ignition dosent like NON RESISTOR plugs..
swapped out barely used B7ES for a BR9ES and runs sweet, jetting is a little off from me messing with it but it responds to airscrew adjustments and more importantly it rips again
wish i woulda connected the dots sooner, cost me first place in this weekends race
the 450 will have less power and will be harder to start, and will be heavier, but to make up for it it will require more maintenance.
4stroke=dead fish