Just bought a used 2006 yzf450 from a local shop, it had been sat for a while in there but still started, on the night I picked it up the shop guy had put a few plug in it for me and air filter, and it started fine. Now when I come to start it it seems to take a while to start up, when it does fire up the header pipe seems to glow after about 20 seconds of idling, not sure if this is normal or not, I also noticed after trying to kick it up for a while a small amount of what looked like coolant on the floor (green/ blue colour), it also seems to be back firing and popping (flames) quite a bit, is this all normal ? do you suggest I drain the tank and carb and put fresh fuel in her see if it makes any difference. Sorry if these questions sound a bit dumb but its my first 4-stroke just come off a 2002 cr250 2-stroke. (Hoping ive made the right decsion) Hope you can help thanks guys.