We've all heard the common phrases before.
"I can't get off the corner".
"I'm stuck to the track".
"I've got too much grip".
They all sound different, but they usually mean the same thing - the kart has both rear tyres planted hard on the track on corner exit. When the kart is stuck to the track, all you can do is mash the throttle and swear at it. It's incredibly frustrating.
Easily the most common question I get asked by new karters is "My kart won't come off the corner, what do I change to get it to accelerate faster?". Unfortunately, the only honest answer I can give without a long discussion about their existing setup and the behaviour of the kart is "Buggered if I know mate!".
A corner is a process. An excellent corner exit is the result of an excellent midcorner. An excellent midcorner is the result of an excellent corner entry.
If your kart sucks on corner exit, rewind the action. Observe the kart at midcorner. Is it working at midcorner? The outside rear should be planted firmly, the inside rear gracefully gliding above the track, the kart in a slow drift through the rear tyre slip-angle. If it isn't, have a look at the reason why, and rewind the action further. Observe the kart at corner entry. Does it respond to steering input? Does it turn in smoothly? Does the rear tyre unload smoothly and stay unloaded? Does the nose of the kart tip into the apex predictably?
If any of these things aren't happening, you're going some way to explaining why the kart sucks on corner exit. The key is to identify the <em>source</em> of the problem and solve that. You'll be far more successful than just trying to get "less grip".