OK cool.
There's a friend of Augie Dog's (from the defunct Motor Assisted Bicycle forum Augie ran for years after leaving this forum.) that lives North of San Antonio who rode his Tanaka 40cc powered Golden Eagle engined bike from his home to the border of Canada to meet up with his wife and relatives, (he put his bike back on the car's bike rack for the trip home..) Interesting trip that was chronicled and it was done in early summer of 2016.
He rode through Texas, Oklahoma, Kansas, Nebraska, South Dakota and finally Minnesota, I think a total of 1900 miles. No problems on the trip and he rough camped at hiker biker campgrounds or stealth camped. His bike averaged about 130 to 150 MPG and every thing was carried on the bike. I'm planning on a single wheel trailer because the bike is already set up for this and my camping gear isn't light weight hiker gear..
From this forum there's BamaBikerGuy who rode his GEBE with a 25cc Redmax weedie engine from Alabama to Colorado and back. I think that was about 2006 or '07. A 25 cc engine! It's cruise speed was about 18~20 mph.
I generally don't pin the throttle on this engine. It's been running so well, I don't want to shorten it's life.