If your circular saw is burning the wood, there are a few possible reasons. First, the blade may be dull and not cut cleanly. Second, the saw may be running too high of a speed, causing it to overheat. Or third, you may be pushing the saw too hard, which can cause it to overheat. To fix the problem, start by checking the blade. If it's dull, replace it with a new one. Next, reduce the speed of the saw if it's running too fast. And finally, take it easy on the saw - let it do the work, don't force it.