sputtering problems 636

I own a 2005 ninja636.When the bike is warmed up,after riding for about 30-40miles it starts to sputter.I changed spark plugs, air filter, drained and replaced the gas,and did a diagnostic check of the sensors (no codes appeared). My next step was to check the fuel pump until I saw a warning on the fuel tank of my 848. It stated that when overflowing the tank , heat may cause fuel to expand and flow into the evaporative emission control system,resulting in hard starting(which  I 've experienced also) and engine hesitation. I have overflowed the tank more than a few times on this bike. Would this warning apply to the 636? If this is the problem, what can I do to correct it?  

If the "sputtering" you're referring to is at small throttle settings, then yes, that's the most likely cause.

The "charcoal canister" evaporative emissions system collects fuel vapors from your fuel tank, then ejects and burns them when the bike starts up and runs. If you overfill your fuel tank, however, the canister fills up with fuel, and then when you start and run the bike at low throttle settings, it's pulling too much fuel into the intake, resulting in an overly rich mixture. You might want to find your charcoal canister and check it to see it's full of fuel.  

I have the service manual for he bike, and it shows the evaporative emission control system for the California models only. It shows the canister and the seperator but apparently, its in a different location on the other models. Any idea where it's located?  

I'm pretty sure that the evaporative emissions control system was standard for all 49-state models by that year, but I could be wrong.

If not readily visible by the engine, try looking underneath the seat/tail-section, or up front underneath the fairing by the headlight assembly.  

Kento,a quick update on the sputtering problems of my 636.First, there is no evaorative emissions control system. I believe the problem may have been the gas cap. The last few times I took the bike out, it didnt sputter, but right after I filled the tank up with gas, I had problems starting the bike. After a few attempts, the bike would start. I blew the gas cap out with compressed air,took it to the track over the weekend and had no problems!  

Cool, glad you found the solution to the problem!