Slow speed sputtering

[2KLuder]

I just purchased a 2005 S4R Monster with 5200 miles. The previous owner seemed to take very good care of the bike both cosmetically and mechanically. He had service receipts for new belts at 3500 miles. The bike runs great, except for when the throttle is just cracked past idle. None of this sputtering happens when sitting still, only when moving. At around town speeds the bike will spit and sputter a bit until i give it a little more throttle. Now the previous owner did core the stock cans but i was not under the impression this would make enough difference to cause this misfire. I checked the chain tolerance and it's around 25mm so its not slack in the chain. To my knowledge there have been no valve adjustments or throttle syncs adjusted since new. Is this sputtering a common problem? Any ideas where to start before i take it to the shop? Thanks guys!

[numbskull]

You're riding too slow.
Seriously, they make all kinds of noise and mechanical noise under 3000rpm. The bikes behave much better at higher rpm. Does it actually sound like misfiring? Does it exhibit any of the same symptoms when you are riding between 5000 and 8000 rpm?

[2KLuder]

No not at all. The only time i feel the symptoms are around 25-45mph around town when the throttle is just slightly opened. The sputtering seems a bit too violent to be OEM. I feel like i'm hearing sounds out of the airbox when it does sputter. Dont get me wrong, it's not un-rideable, but i dont think it's correct either.

[numbskull]

Hmmm...My bike does the same thing but at lower speeds and at partial throttle. Granted I don't have the same bike, but mine burbles and is noisy at partial throttle, it was much worse when I was running the bike in stock form but with the DP ecu and full exhaust it's much better, though it's not sputtering like your's. I would have the throttle sync looked at carefully. It just may need a small adjustment.