This last weekend at an enduro race there was a long heavy section with lots of climbing through loose rocks and large boulders. On my practice run the bike overheated twice so i stopped and let it cool off a bit before starting it again each time. But on race day on my 1st lap the bike overheated in the same section i stopped just a bit to let it cool off but people started to gain on me. So on my 2nd and 3rd lap i didnt stop eventhough i could hear the rad coolant boiling over, and tried my best to use the clutch the least i could and to keep my pace up to finish that section, cause i knew that after it there was a wide open section were the bike would cool off. My question is: 1) How long after you hear the hissing sound of the coolant boiling over can you keep on riding without affecting your engine? 2) On my 2nd lap since i didnt have any coolant with me i poured some water from a water bootle i had nearby at the pits on the radiator to compensate for all the coolant that was lost. Just guessing It was around 300 ml -500ml. Would this ammount of reg. water affect the hoses? Should i drain it and fill it up with coolant? Thanks!