I did some stuff:
1. Swapped out the condenser
2. I cleaned the exhaust pipe. Wasn’t toooo dirty.
3. I checked the gas tank vent tube and it is clear.
I’ve not been able to commit much time to the bike, obviously, and I’ve done (nearly) the least I can do. But I have eliminated three of the possible options.
After doing the above, I took it on a test run:
When I cold crank it, it fires up no problem (as it always did). With a crank or two it goes quickly from put-put to the crisp popping sound of combustion in the chamber and it’s running great.
When I ride it for even only a few minutes and then kill the engine, it won’t start back up. I can hear the put-put-put as I pedal crank it trying to get it to run again, but there’s no combustion happening. It never fires back up... Endless crank putting.
When it cools off, it fires up again.
So, I’m still inclined to think it’s a heat related problem. There are many things I intend to try (based on y’all’s suggestions), but if anyone could help me prioritize my tasks based on the symptoms and what most likely would fix the thing, I’d much appreciate it. I guess I’m trying to do the “fixes” that would cure the problems (dying when too hot, not starting when warm/hot) that are only cause by the engine being hot first. Then go from there.
1. New spark plug, properly gapped at 0.019" to 0.022" thousands of an inch. <--(the old spark plug is only one year old, but I can change it)
2. Get a compression gauge and check compression and hopefully I don’t need a new piston and kit <--(are there other symptoms/signs that this might be the problem? Rattly noise at high RPM, maybe?)
3. If bad compression (from above test) could be the seals... “Sometimes crank seals hold until the engine warms up.” Check for bad crank seals to see if the piston is pulling in leaked air instead of fuel/air mix. <--(not sure yet how to go about this yet, but will figure it out, I suppose...)
4. Clean the points well and gap them, check that the points lobe is in good shape inside the flywheel. <--(visually speaking, everything looks nice and clean in here, but I haven’t checked the gaps... Is this something that would only be a problem when hot?)
5. Plug the decomp
6. Check to see if the internal HT coil is dying <--(any tips on how to check this? And, again, would heat make this a prob?)
7. External coil?
8. Ignition wire and cap?
9. Check the timing?