Circular saw blade binding and motor smoking – help!

Hey guys, been using my Makita 7-1/4 circular saw for a few months, no issues. Today I was ripping some 2x4 pressure treated lumber and about halfway through the cut, the blade started binding, saw bogged down, and then I smelled burning and saw a bit of smoke from the motor area. I stopped immediately. Blade is sharp, depth is set right. Could it be a motor issue? Or maybe the battery is dying? It's a 5.0Ah battery, was around 3 bars when I started. Any ideas?

Classic signs of a dull blade or dirty arbor. But if the blade is sharp, check the arbor nut – if it's loose, the blade can wobble and bind. Also, pressure treated wood is tougher than regular lumber, so the saw might just be struggling. Could be the motor brushes are worn out after a few months if you've used it a lot. Pull the brushes and inspect them; if they're less than 1/4 inch, replace. I'd also clean out the sawdust from the motor vents – sometimes they clog and cause overheating. Let us know what you find!

Agree with Rick, but don't overlook the battery. If it's old or been dropped, cells can go bad and cause the saw to draw more current and overheat. Try a different fully charged battery. Also, check that the riving knife (if equipped) isn't bent or misaligned – that can cause binding too. And make sure your shoe is flat and not warped. One more thing: are you using the correct blade for the material? A framing blade (more teeth) might bog down in PT. Switch to a ripping blade with fewer teeth if you're doing a lot of ripping.

Thanks Rick and Mike! I checked the arbor nut – it was tight. Brushes look OK, still around 1/2 inch. Cleaned out the vents, there was quite a bit of sawdust. Tried a different fully charged battery (same 5.0Ah) and still the same issue: bind and smoke after a few inches into a cut. I'm using a 24-tooth framing blade, which I thought was right for ripping? Maybe it's the blade? But it's only a couple months old. The riving knife seems straight. Should I just get a new saw?

Hold off on buying new! That 24-tooth is fine for framing, but if it's a cheap blade it might be warped. Put the blade on a flat surface and see if it rocks. Also, check the blade flange for burrs – they can cause runout. Another thing: the motor bearings might be failing. Does the blade spin freely by hand? If it's rough or gritty, bearings might be shot. If it's smooth, try a new high-quality blade. If still no go, it could be the armature/commutator – time for a warranty claim. Don't toss it yet!