I took a look into my coolant resorvoir tank and it looks pretty low. I also see little air moisture bubbles inside. I checked my coolant with the bike straight up not on the kickstand. I bought coolant today but everyone i hear drains there coolant i just want to add not drain can i do that or do i have to drain it and replace it?? By the way i have a 2007 RR just did an oil change and have 4747 miles on it. What do u guys suggest??