Greg

How tall or short is the driver? What type of kart is he driving?

Can you install a flat bottom seat, and lower it all the way down?

Maybe slide the seat a little forward? anything that would create the kart to wanna pancake, maybe try a soft axle?

You mention he’s a the right legal weight, but do you have to ad weigh to the kart at all, or he needs no weight at all?

What kart? Seat style and location is definitely priority #1 when dealing with a larger driver. While you see many successful tall drivers in classes like tag, they all have something in common. They are skinny and don’t have much muscle mass. Even at 6′ plus they are 170# max and a lot of that weight is long legs. They essentially mount their seat in the same position as a 5’8″ 150 driver. What I’m getting at is basically very few think outside of the box in regards to seat mounting. Because of my size you won’t ever see me in a standard seat mounted mounted in the same way as you typically see.

As far as setup goes, if you are seeing the inside rear wheel drop too quickly, it’s because your rate of lift is too quick, obviously because of your driver’s size.

Max rear width is a must, as well as taking caster out of the front end to try and settle that lift down. If you slow down the lifting action, it will have a longer duration.

This might even be one of the rare occurrences where you throw the rear torsion bar in to see if you can limit the flex in the rear.

Greg

Remove front torsion bar, go 2-2 on the camber and toe, try hard axle, 2 seat struts on each side, and 54″ at rear track, move the seat about 2″ to  3″ forward and lean it back about 8.5  to 9.5″ from lip to axle.

I am not an expert, but with my fat ass, and my hight this seems the only thing that works for me.

I hope this helps, or at least give you a good starting point, and if he doesn’t like it, then you can put it back where it was and try something else.

And after that if he doesn’t like it, tell him “life is not for everyone” No, I’m just kidding, sorry. Lol