hey everyone, im not too familiar with bikes yet, i am a ASE certified diesel and marine mechanic and know most cars very well...here's my problem
BIKE: 03 CBR 600RR 7500 miles w/ a D&D exhaust

I've been running 93 octane in my bike, but recently found out it simply calls for 87...but 93 is a cleaner and hotter burning fuel so I doubt that would've done anything harmful.

at low throttle (in 1st and second) it's very hesitant and sputters a lot. almost sounds like one cylinder isn't firing but once I roll on the throttle and reach higher speeds it seems to run fine, possiblility a spark plug could be fowled,

so far i've drained the tank of brand new fuel to see if i could get setiment and/or water out, i put new 87 and fuel treatment/injecter cleanerin, but no improvement yet. Anyone have any ideas?[/align][/align]replace plugs? i need help guys, thanks a lot![/align]

 

plugs are cheap and relatively easy to replace. I'd try to get some Iridium plugs for it, they last a lot longer and resist fowling very well.

Seeing as your ASE, I'm gonna think you may have a laser thermometer. If not, try to borrow one or buy one and check the individual headers pipes to track down which cylinder is missing.

 

+1 on the plugs and check the air filter. Does it have a slipon or a full D&D exhaust system? If its a full it prolly needs a PCIII and tuned. Same if it already has a K&N or BMC air filter. May try running some seafoam thru it.

 

found out it was the plugs,. i started it up and sprayed water on the header and turned on the far right (cylinder 1 or 4?) wasn't firiing like the others. got some plugs from the dealer and swapped them out and now it runs perfectly, and as far as the exhaust goes, what exactly is the difference between just a slip on and a full? my D&D slips onto the collecter on the header...so is it full or just a slip on?