(This includes ideas from members of the “Honda Rebel 300 500 1100” Facebook Group.)
Check tightness of both battery terminals – stalling could be caused by a loose battery terminal.
Keep in mind the bike shuts off if you put it in gear with the kick stand down. Also check the kick stand switch – it could be loose.
Operate the kill switch about 20 times, which cleans the contacts. Kill switches sometimes are a problem.
It might help to use Seafoam in the gas tank – in case you got some bad gas.
When the bike stalls, loosen the gas cap and see if that helps.
Make sure you are not overfilling the gas tank by topping it off. If you did recently, open the gas cap to let some of the vapors out. Also check your crankcase breather tube (near the kickstand). It is a black tube with a clear end. Remove the cap and empty any liquid trapped in it.
Make sure your maintenance is up to date. The schedule is in the manual. Check your air filter. It’s not due until 16,000 miles, but some are dirty before that. I changed mine at 4,000 miles. That by itself would not cause the bike to stall though. I would make sure the spark plug wires are pushed on tightly.
If it idles too low, maybe the idle speed needs to be increased.
Rebel500 