Welcome to the forum, glad you joined us
Well lets see, I've done 140 miles, 100 miles, 70, 60, 50 ,40, 30, 20 and I dont stop every 30 minutes. I have ridden for hours non stop. And this is in the 110deg. AZ heat
But I do take it easy and cruise 20-25mph. I use a good quality 2-stroke oil and do a lot of maintenance to my bike. I have more problems with the bicycle then I do my motor.
I've been running my motor for 5 years and well over 4,500miles. But, I did a compression check the other day and she is getting tiered.
One of the best ways ( In my opinion) to keep these motors running is to leave them stock with no performance upgrades.
Bicycle Motor Preperation And Care Maintenance Schedule 