Re: 650 thunderbolt Stalled and won't start
Well, first things first. You will need to check for spark. Best way is to get a spark gap tester from an auto parts store. You have to be careful with those 3cyl 650's. If you short out the ignition, it's going to get expensive fast. The tester is worth the few bucks.
Test the spark on all three cylinders. If you have no spark at all or only spark on one or two then you have an ignition problem. There is a CDI test that will need to be done on the switch box. I can't post it for some reason. It keeps telling me it's too large. Look around on the site and find the test procedures for the 3cyl box.
Other things to check for spark problems in the meantime. Pull the cap and inspect it and it's contacts. There is a little spring loaded contact at the center that the rotor revolves on. Check that for cracks and condition. Check the cap in general for cracks. Also make sure it is seated well and the contacts are clean. Also check the coil. I recommend pulling it off the side of the engine and out of the holder. Check under the rubber isolation boot as well. They had a tendancy to crack and short against the block. Also try disconnecting the mercury switch that kills the engine when the motor tilts up. Those were known to go bad as well. It is a little silver cylindrical shaped piece that screws to the block and has a wire that connects to the switch box. you just need to disconnect the wire to test.
If you have spark at the cylinders, then you have a fuel problem. Fuel pump and carbs should be the focus then
