I bought a well-used 2006 Rev-3 270 that had fried main bearings and in general a worn-out motor. I just did a total engine rebuild (top end, crank, bearings, seals etc). Bike starts and runs great! Stock Mikuni VM26 carb with #140 main, 27.5 pilot, needle clip 3rd position (middle), air screw 1.0 turns. Unleaded premium fuel with Maxima 927 at 60:1 and stock heat range spark plug (NGK BP7ES) stock ign timing. Motorex pre-mixed coolant. Waterpump housing, seal and impeller in good condition.
I ride at sea-level mostly and have run about six tanks of gas thru the bike riding around the property, the majority of the time crawling around in 1st and 2nd gears, ambient air temps 70F to 85F. Whenever I first start the bike from cold the fan doesn't run until I've been riding for 10 minutes or so. After that the fan runs constantly while riding. I'll shut the bike off for five or ten minutes and upon re-starting the fan is running. I haven't yet been able to intersperse slow speed riding with any faster riding (3rd thru 6th gears) to see if more air moving thru the radiator will cause the fan to shut off?
My question is; how often/long should the radiator cooling fan run? Is this normal for this bike or do "they all do that" ?
Any info appreciated!
Thanks, Dorian