I’m happy that Scott was able to get Kieran’s problem solved. And, the clutch was where I was going to suggest looking as well, when I heard of the issue with slow launches and spin recoveries.
The clutch we got with our WF had Yellow springs. I bought another clutch without checking what was in it, only because it was CHEAP. Since we run the sprocket inboard, I took the unit apart and swapped the direction of the pucks, noting that it had orange springs, which are supposed to be the stiffest?
Colin immediately noticed the improvement in launches, and it got better as the clutch wore in. Yes, we also did several track days for him and brother Connor. I’d suggest reading up on the expected engagement RPM for the various springs. If the clutch is engaging shortly off idle, and/or locking well before the designated engine speed, then there is an issue.
FWIW, the only time we experienced the issue both of you described was when an outrageous gear was selected for an event in Oscoda. Colin was in charge of choosing his own gears, and I let him put the 56 rear on (16 or 17 front, I forget…) although I knew it was not going to work. Was it slow to get going? Ouch! Tight corners meant it took way too long to get up to speed again. After the event, we devised a method of checking for his actual top speed capability with a run down the long taxiway. 67 mph when the limiter kicked in. After that, I handed him a calculator and had him first estimate his actual top speed potential, based on course design, then choose the gear based on what we knew the other one could achieve. That is when the wins began. Good times……