You don't mention what your ignition setup is but when the engine is hot and "barely turns over" unplug the coil (no spark is what you want), that will eliminate ignition as an issue if it still barely turns over.

If it turns over normal then it's an ignition related issue.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.