FZRSupport: the FZROnline Archive

Over the last month or so my '98 FZR600 has started running a little rough.

We're in the middle of the hot Austin summer, and I've had to do a bit of start & stop errand running lately, and the main symptom seems to arise from that.
When the bike is real hot, and I get stuck at a couple of lights it seems to run rough.
It idles fine, but acceleration / power seems a little rough.
Sometimes I can feel it miss / pre-ignite.

I just checked the valves about a month ago as regular maintenance.
All were within spec and closed it back up without messing with anything.
Also replaced the plugs. (but not the wires)

Hey guys,
I am BRAND NEW to this site, And Brand NEW to the FZR world. (sorry for posting this under your post, dont know how to creat a new post, has relevance though)

I just bought a FZR 1000 from a guy on craigslist, seemed clean, engine was rebuilt a season or two ago, marked at 43xxx miles. The guy said he brought it to a mechanic and had all the correct maintenance done, carbs, oil plugs etc.. Brand new tires, brand new battery, fresh paint job,clutch seems decent, shifts well (neutral light stays on constantly though)
Well I finally brought him down to $750.00 including delivery. I jumped on the purchase because it ran smooth and seemed like an incredible deal.
HOWEVER, today (in the 97 degree humid weather) I was riding at around 40 or so in 3rd gear, and the engine just started bogging out, I gave it gas- nothing. Pulled over, cranked it up and revved it hard in order for it to stay on. I rode home easily with no issues.
What can the problem be? I am a broke college student, and not mechanically inclined at all. Don't want to pay 225 to have "already cleaned carbs" cleaned again... UNLESS ITS AN ABSOLUTE MUST. (I can probably sell the bike at a profit if need be, but I like it a lot)
Do you think the bike was a good purchase? the guy seemed to just be happy to get it off of his hands since he's planning a move to Florida mid October.
All help would be much appreciated! Thanks in Advance!
P.S. Engine was rebuilt by previous owner, so I have no info/ receipts about anything.