Why is my RF600R shooting flames?!

Q. I got on my Suzuki RF600R today to go home from work, and the first thing it did when I tried to start it was backfire and shoot flames. I thought what the hell, maybe these things happen.

When I then went to actually go home I noticed the bike didn’t want to rev past 4000rpm (without a lot of encouragement), and the exhaust sounded like it was gargling, is it just a case of a spark plug not firing or something more sinister?

There’s no smell of petrol, just a bass note in the exhaust that sounds like a V-twin, that wasn’t there before.
Rf600r, email
 
A. It sounds like a misfiring cylinder, so it could be a fault with the ignition coils or leads. You can determine which cylinder isn’t firing by spraying water on each exhaust downpipe to see if one is cold.