Kawasaki kx85 help Oil ?

[David]

My friend said change the gearbox oil every third ride should i do that or change it like 2 times a year as it would cost a lot to change it after every third ride and what should i do to keep my bike running smoothly.

 

[Robert F]

as long as the oil is clean go with it , the oil itself doesn't wear out

 

[imported_G B]

Being that it only holds about 2/3 of a quart you could probably afford to change it every time you rode, but, that would be quite unnecessary.
Just change it on a regular basis or more often if you ride in alot of wet conditions.
Regarding keeping your machine running smoothly, just follow the maintenence schedule (with particular attention to the airfilter).