This weekend is championship time for two different series, one local and the other international. Both events wind up racing for this year. • East of Fernley the desert racers of MRANN square off for their final event. The pits are located on the south side of I-80 off the Nightingale exit. Titles will be clinched while other racers are riding to secure their places in the points. The action begins Saturday with a 45-minute race for the Pee Wee riders. Then, at 11 a.m. the Mini Bikes/Women/Vintage and Bombers begin their 90-minute event. Sunday is for the big bikes