So, a lil bit of background about my hornet: I have a 2007 919, pretty much everything is stock on it, except the colour and the muffler, which the previous owner has removed the baffles. I live in Canada where the temperatures go way below zero. During the off season I keep my bike in a non-heated garage and I winterize it.
Until yesterday I used to start the bike every weekend or so and let it run for 5-10 min. I thought that it would be good for it. But, since last weekend I have an issue.
So I start the bike as usual with the choke on and let it run. The sound was good as usual. My fault was that, by mistake, I reved it too soon and a bit too high. As soon as I did that my exhaust sound changed. Also it backfires once in a while. I know I shouldn't have done that and that it's not good to start it in the winter. (I found out yesterday) But unfortunately, it's too late now.
My question to all of you bike savvies is, can you please help me identify the problem? (it's winter now and I'll have to wait until end of March to bring it to the garage. Nonetheless, I want to know how much money to put aside.)
Here's the regular / normal sound:
And here's the sound that I filmed this weekend :
Thank you everyone for your help! Much appreciated!