Im fairly new to the cbr world and I bought a 2000 cbr600f4 a week ago with 12k miles on it. I've ridden about 300 miles with no problems. But recently I've had an issue when its hot out (above 95 degrees) and riding for longer then about 20 minutes straight. It will start to run rough. Then wont idle and stalls. And wont start back up until its cooled down for a few minutes. It cranks but wont fire. Any suggestions?

 

Talked to a couple people and they seem to think it could be the coils going badbor possibly the cdi box.

 

Download the online pdf of the factory Honda service manual. There is a thread here in the F4 section w/ links. Start working thru the troubleshooting procedures to find the cause.

We need to have much more detail of what's actually happening to make any kind of informed recommendations.

You could have a fuel feeding issue (lack thereof), thermostat (cooling system) issue, R/R issue, etc...

 

How is being ridden, and by that I mean, are you riding for 20 minutes at speed, and while cruising along it starts to run rough?
Or you've been riding for 20 minutes, and while you're in stop-and-go traffic it starts running struggling at idle? If that's happening, will it smooth out when you hold the throttle with the revs a little higher (like 2k or higher?).
There have been lots of threads over the years about the stock regulator/rectifier ("r/r") overheating and failing. I think the reason it becomes a problem after riding for 20 mins or so is that the engine is hot, and the fan is going to come on. When you're sitting in traffic at idle, the headlight and the fan are drawing a lot of current.
I replaced the r/r on my F2, found the one on my f3 had melted connections and replaced that, and I've just this year replaced the one on my F4.

There are details in the service manual on how to test it, and I bought my aftermarket one at regulatorrectifier.com. They replacements have better case, with cooling fins.

Of course there is still a chance that there is a fuel delivery issue.....