Hi, I have a 1991 CBRR 250. Recently I have started noticing a flat spot around the 8k rev mark when giving it horns this has only just started to happen in about two weeks of riding once a weekend. Just yesterday I went for a ride and all seemed ok and went ok. Today I went for another ride and was giving it a bit. In third gear I heard a whistling noise so I backed off and changed up. I was getting a pretty pungent burning smell and worse of all when I give it a about a 1/4 bit of throttle it doesnt really go and makes GRRR sound like something is misfiring. If I just trundle along it seems to be ok but still very flat better in 1st, 2nd. Also I filled her up with BP 98 for the first time yesterday as opposed to 91 as I have heard this can clean things up inside the engine. Is this anything I can fix (Basic/medium tech skills) or check or should I take it to a bike mechanic first off... and if so can anyone recommend someone in the city/Albert park region... in Melbourne. Added..: The idling either hot or cold is slightly rough. not sure if it is related. There is also a high pitched ticking sound, I am thinking the tappets and the carby need a clean ? Thanks !