stock engine

Hi All— Really struggling here. I was riding fine at 30mph and slowly came to a stop when engine idled down and died. Can’t get it to start and there is a noticeable “squeak sound” near the cylinder area at the END of the rope pull only. I have inspected clutch, cleaned carb jets, inspected...

I have a 26" hardtail MB, stock engine, and a 44 tooth sprocket. I usually ride at 30-32 mph, 32 being at the max RPM I feel comfortable taking the HT to. I could twist the throttle more and rev higher, but I feel the engine will grenade if I rev any faster. So, what RPM am I turning at? If...