Backfiring and just up and dies

Hi all!
This is not how I wanted my first post to go
Name is John, and I'm from Edmonds Washington. Just bought a 2008 SMR450 for my wife and she has been blasting around on it for a few days now.
It has started to backfire and die as she is riding it. It won't run above about 2000 RPM now without backfiring and quitting.
After doing a bit of research I thought it might be the fuel pump lifting. I filled the tank, and it was low enough to make me think that could be the problem. Still backfires and dies. The pump primes and the bike idles great, but won't run at higher RPMs.
It did have a Dynojet Power Commander V.
I would love to hear your theories.

Thanks!
John

Sounds like a bad battery at first impression. If it's a lithium, I'd suggest holding a volt meter on it at idle and check DC voltage during idle and revving it up. Easy place to start. I had an identical problem and was scratching my head until I checked voltage. The internals came loose in the battery so when the engine revved it caused vibration and voltage dropped to 6 vdc
Welcome aboard btw

tighten (and check) all of the connections too.

Thanks for the replies guys!
I did check the voltage and it was charging at over 14 volts off idle. Battery voltage if I remember was 13 something. I know the battery has juice as I tried to start for quite a bit and it cranked really strong for longer than I thought it would.
I thought it might be the fuel pump problem so filled the tank to the top....still ran rough over about 2000 rpm and popping/backfiring a lot!
Out of town this week but I will try and check all connections for corrosion and tightens next week. One suggestion was taking the Dynojet Power Commander out of the equation. I didn't want to try that until I exhausted all other avenues. I wanted the bike be use it had low miles and was running fantastic when I looked at it. We ran it for about a week after....and it ran great! Then one afternoon it just started running like crap and backfiring then would die at stops!

may well be the fuel pump zip tie has come loose in the fuel tank

I was hoping it was as simple a problem as the bad zip tie but I filled the tank to the top just to test and it still runs like crap. I thought that would be a good test to see if it really was the pump lifting......or could it still be a problem with the pump and I should still remove to have a look? If the fuel pump lifts......could the be a connection problem in there?

Did you check voltage off the battery while revving the rpm like I said or just at idle? The point I was driving home is the excess vibes from higher rpms may be causing an electrical short in a faulty battery or loose wire. My battery appeared perfect from idle but once the vibes kicked in, she shorted out. Once I removed the lithium battery, I shook it and it sounded like a horocka. If you have a standard lead acid battery then it's probably some other electrical issue. I hope you get it figured out soon.

Yes, checked battery with engine off, at idle, and at higher RPMs. Got good readings all around.
It's really strange, the bike was running fantastic one day and crap the next. As soon as I get back in town I am going to check all connections again and then pull the pump to see if anything looks out of place.

Just for the heck of it replace the spark plug.