i have a 99 ninja zx6r with 14,000 miles. it has just recently started having a little sputter in it and has been backfiring. it doesn´t do it at idle just when im goin down the road. it has died about three times when im riding it and wont start right back up. if i turn the key off and wait about 30 seconds it seems to start right back up after that 30 sec wait. over the winter i had to have a new timing chain adjuster put on it and it ran fine after. he did put 2 gallons of turbo blue racing fuel in it and i burnt it out riding it and added regular unleaded plus 94 octane. my guesses are either my spark plugs need changed or maybe some water in my gas. if anyone has any idea what the problem could be please help me out. thanks youre help would be greatly appriciated.