If you’re bicycling you have too much weight transfer happening. How tall are you? You might want to double-check your seat placement to see if you can get laid down or back a bit more and get less transfer.
Other things you can do to help the kart transfer less weight include:
– Less caster
– Narrower front track
– Softer front bar/removal of front bar
– Less seat struts
Keep the rear at 55, narrower will make the problem worse.
If there was a variance of 1.25s in your lap times, you probably still need to iron out your driving some more as well. Of course you want to be as consistent as possible and that will help you get a better feel for how the kart is reacting handling-wise. Consistent driving = consistent handling.