TANAKA 33 test case and tip:
Gene and Dwight are retirees, and they ordered 2 bikes, a grey and a gold Sun Comfort Rover 21 speed.
I had one engine on hand, I put it on Gene's bike, and Dwight's arrived a week later. So Gene's engine had a 100+ mile head start.
They put on identical speedometers, the 100 mile headstart still shows on both odometer readings. Gene's bike is ALWAYS a tad faster, always gets a tiny bit better mileage. Both are getting stronger, but I told Dwight to sneak off and make up for the imbalance.
If you will do the following, your bike engine will do the same:
Use 89 name brand gas and good oil. (Amoco 89 is my fav).
Crank it up, take a very short run to make sure nothing is loose.
Then take a 10 minute run, stop for 10 minutes and repeat. 10 on, 10 off.
Don't hold it at full throttle very often on that first tank.
You look down the road, run the throttle at 1/2 until you reach the oak tree, then up it a little, 3/4 till you pass the red mailbox, 1/3 to the Moore's driveway etc etc etc. Keep picking targets and varying that speed. No steady speed over 20-30 seconds.
It won't take long to get the hang of it, up a little, down a bit on the engine. Start popping it up to wide open every now and then.
Hold back on the wide open throttle for long distances, however, until you get at least 100 miles on that piston/cylinder combo, else you will get in a rut, and NEVER catch Gene and Dwight.