Originally Posted by firstname.lastname@example.org
THINKING MIGHT BE STARTER....
that thinking would likely be correct. Since the starter is very close to the headers and exhaust a weak starter becomes weaker as it gets hot.
Once it gets hot enough it starts to pull a lot of amps on the battery because the resistance gets so high.
Options= pull starter and replace, or pull starter and take it to autozone and have a load test done on it. However a cold starter may test good .