Hi all, I have a CBR250R with 300kms~ nearabouts that has recently started having problems at around 6000rpm. I'l take off alright, go to second, hit around 6k and I'll get spluttering and a lack of urge. Sometimes I can persist and push through it but generally it's a no go. If I'm at speed and hit the 6k problem area I can drop down a gear and it's good again. I've recently fitted a Yoshi slip on but I don't recall the problem happening directly after that. I'm sure it was good for a week or so. I had thought it was a user problem with starting off in a 2nd or something but I gave it a run tonight and have ruled out shitty gear changing. Any tips on what I should be looking for?