In the past couple of months I've noticed a loss of top end power, instead of the power increasing rapidly after 7/8k RPM, it seems to pretty much make the same power from 8k all the way to 12k.
Bike has about 25,000 miles and has been serviced regularly with oil. Has not had valve clearance checked, I will have to do it soon.
Chain and sprockets are just a few months old. Had correct (iridium, not that it really makes a difference) spark plugs 12 months ago. Clutch isn't slipping. I haven't checked compression recently.
I'm thinking of putting in a new air filter (K&N?) and cleaning the carbs out. Carbs could do with a balance but that can't be it.
Does anyone have any ideas?