Had belts and oil etc changed in november just gone..had 2 short journeys but went out today and bike just wasnt performing and kept spluttering and losing power but was fine over 70mph...temperature gauge was up and down like a yoyo and droppin of revs a tiny tinny splutter from front of engine in lower gears.. .timing belts be out ??? Stump
If the bike performed in November after the belt change, than there is nothing wrong with them now. Must be another issue.
What I would do; change my Fuel filter (clogged) fresh tank of fuel and a injection cleaner. My guess is that that should do it. It could also be electrical, but I put my money on the fuel.
Stump if your temp guage was jumping up and down then I disagree that it is a fuel filter issue, much more likely to be an electrical earth issue. What bike is it?
As above for the temperature gauge issue, mine used to do the same. From memory take off the left fairing and the sensor is that side. Mine was a simple loose connector.
Like I said could also be electrical....but saying it's was in storage from November my first guess is fuel. Anyway I hope it's just a connector.