Need to get a new carb on my 04 Sportsman 600 to replace stock damaged one. I got a suggestion to go with a larger carb and to get a flatslide rather than a round slide carb. My question is what would this affect on the quad and what would it take to put in?

 

A larger carb will give you more top-end power at the expense of some torque down low.

In some instances, too large of a carb will cause drivability issues...like trying to go slow on a tight trail at a steady speed, the machine surging, or running poorly due to the low velocity of the incoming air. Unless the motor is built (head work, cams, higher comp.ratio, etc.), I wouldn't waste the extra $$$ on a bigger one.

You'd get a bigger, better increase from changing jets on the stock carb, imo.