Engine sputtering

[cdndrtbke]

I noticed this past weekend that when I am in a higher gear (4th and 5th) but I am not going that fast and I hammer the throttle, she sputters like crazy. It has never done this before and was wondering what the problem could be? Clogged jet or something? Thanks in advance. I tried posting this in the XR400 section but no one has answered, thats why I'm posting it here as well.

[captb]

If you havn't allready I would drain the float bowl into a glass (brass screew in the bottom) see if you see any trash or water and make sure the fuel keeps flowing steady, make sure the choke isn't sticking partially on the lever can be off but the choke butterfly is spring loaded, if not maybe a partially plugged jet, check the spark plug, I've seen a piece of carbon or flake in across the electrode, maybe leave the fuel cap loose and see if it changes the vent could plug up, check the wires around the coil maybe arcing under load or loose plug in or ground, good luck.