If you have the later model electronic ignition you'll just have to replace the ignition assembly. No other choice. But that didn't show up until the very late model Red ones. If I remember right. If it has the point type, you're in better shape. You need to look for everything to be squeaky clean. Pull the flywheel and the saw down with cleaner of your choice. You have to watch for light oil coating on the wires going to the condenser and the coil, plus on the points. Use an electrical contact cleaner on these parts. Carb/brake cleaner won't work. Contact cleaner evaporates fast and doesn't leave a residue. You can test the condenser with a digital ohm meter. One lead on the wire end and the other on the case of the condenser, you will notice the meter climbing or decending numerically. Now switch the leads. You should see the meter doing the exact opposite. I.e. With red lead on wire and black lead on condenser case the ohm reading will start climbing slow and steady. Now reverse the test leads and the meter will start slowly dropping. If you get only one direction (climbing or dropping) or no change at all the condenser is bad. You have to do this test with the condenser removed from the saw and on a wood surface. I've never seen a coil on a point type system go bad. It's always the condenser or oil coating the wires. 99 % of the time it is oil. If cleaning all the pieces doesn't work, you still didn't get it clean enough. So do it again.