When the engine quits I could remove the plastic cover off the flywheel. The block and head are closely cowled with plastic to duct the air around the engine for proper cooling.
It wouldn't be too easy, by the time I get all the covers etc. off, it would have cooled down and then its easy to restart.
If it is running too hot (lean), how about purposely adjusting the mixture too rich, and see if I have the same problem after 45 minutes of driving full tilt?
Let me know what you think, thanks, Dave