Will running my headpipe mess up the engine on my 2009 Honda CBR600RR?

I've seen lots of people say it's bad and others say that it won't bother the engine at all. So can someone please give me an answer. I've removed my stock exhaust and left just the headers on my bike. It seems to run normal, it's quite a bit louder though. This is not a permanent thing, just something I thought about doing for a couple months until I can get a full exhaust kit.

I'd be more concerned about getting a defective notice from your local constable.

It will both mess up your engine and mess up your house when your neighbors start throwing rocks and eggs at you.

I don't understand noise makers. Whether it is on rockets or hogs. The only person who enjoys the sound of your bike, is you. So unless you live in the middle of nowhere and don't have a neighbor within half a mile? Put your old exhaust back on or the police may show up with a noise citation.

Just sayin.

And when you fit the full exhaust you can replace your valves - very expensive experiment you are conducting.

Thanks for all the answers guys, seems as though removing my exhaust is a bad idea, I believe I'll just throw the stock one back on until I can get my full exhaust kit!