Surging at hiway speeds

[hop]

i’ve been noticing that the scoot seems to be surging a little at over 50 mph. It’s not jerky, but definitely noticeable.

Fuel tank looks clean inside (what I can see). I’ve runs only ethanol free gas i. it. Ran some injector cleaner in the gas last week.

Oh the tach looks steady..not seeing an rpm change.
Any ideas?

2104 Forza, 20k miles