In my experience working with drivers complaining of a snap loose condition, it is almost always a result of an under-steer condition first. The driver believes the kart is turning in, but there is not enough weight being moved to truly initiate a smooth turn. What happens is that the kart begins its initial turn in, but is sliding the front a small amount. When the kart gets to apex, the kart has lost enough speed to allow the front tires to stop slipping and gain the traction they needed to not only initiate the turn in but the full rotation needed for the turn.
Now the hard part: What is not working?
I look to weight placement and seat mounting. As a tall and heavy driver, 57-59% rear weight has worked best for me on the Margay. I would have the seat tilted back at about a 45-50 degree angle.
I also used long front hubs on the Margay to stiffen the spindle arms.