*Top end………… Try to do it more often than every 25 Hrs, if you wanna stay competitive
*Bottom end……….. Seems about right, as you mentioned
*Brake fluid……………….Check it every time you get the kart ready for the track, but you’ll find out soon enough that it will require a flush a lot sooner than a year. Almost every 4 to 6 months. These brake systems work on some extreme temperatures and abuse.
*Transmission fluid…………… Every other track day, or every other race. ( NO MORE THAN 2 )
* Fuel filter………………….. Every 4 to 6 months
That should get you in pretty good shape, and be more reliable.
Hope this helps.