So I went for a ride the other day on my 02 Kawi 500R and was having trouble shifting into gears higher than 3rd. It's like the shifter was just jammed or something and wouldn't move up into the next gear. Eventually after 3 or 4 tries it would shift. I've put about 8,000kms on the bike since I bought it, bringing the total to 28,000kms and have had no problems before. Could the clutch need some work? something in the gear box? I'm new to all this bike tech stuff and don't really know where to look for a solution to this problem.