it's been a bit of a journey getting the fueling right on my girl but I think we have finally got there. Early on she had the usual problems with surging, throttle snatch and fuel cut on decel.
I initially went with a PCV and a custom map. Initial impressions were it was better but really all it did was mask the issues. Then I fitted a full Yoshi system and K&N and we re-mapped the PCV. Got a few more HP and a decent torque curve, was huge fun to ride over 4,000 RPM but still not right.
Finally yesterday we re-flashed the ECU with Woolich software. Did the usual tweaks, removed the fuel cut, dropped the fan temp, disabled the 02 sensors and exhaust valves. Then we went to work on the ignition, totally remapping it. We had a suspicion the secondary butterflies were playing below 4,000 rpm so looked at that as well. I'll be honest it all looked a bit like playing with a black box to me. Then we put her back on the dyno and tweaked the PCV map.
Result: different bike!!
It is so smooth from 1,500 RPM, can hold the throttle anywhere, roll off, roll on, no hesitation, no surging, no fuel cut. It's even smoother and accelerates harder everywhere. The difference was so stark and gave me so much confidence, for the first time I split the traffic at 50 -60 kmh. No longer was I worried about wrestling the bike.
The tuner commented it felt like a GSXR! Like it should have been from the factory.
Yeah I wasted some $$ getting to the re-flash. If I were doing it again with hindsight I'd re-flash first and see what was needed from there.