Recently my engine has developed a flat spot at around 6.rpm and tends to clear around 7ish but somtimes will it will go further.It ticks over smooth and somtimes will rev clear. I had it down at tts last august for jetting and rolling.the car has been going well but this flat spot is driving me crazy ive had the carbs off cleaned them out.cleand the tank and filters.new plugs.tried different coils.going to try a different cdi unit this saturday and if that dosent work then it looks like its going to be the long trip back down to tts any help would be great thanks..

I have fitted a TTS jet kit and that has worked well although I have only done 500 miles with it.

Check for air leaks between the carbs and the engine. I was told to spray a bit of WD40 round the seals with the engine idling. if the revs go up, it means that it is sucking air (and wd40) through a gap somewhere.

R1s naturally are a bit flat around 6000 so if you have a slight problem, it is likely to be around that speed.

Are all of your slides moving freely? As my carbs protrude above my bonnet slightly, I occasionally get the front carb freezing up on me!

It would also occasionally stick, but a bit of slide-swapping soon sorted that, plus the occaional squirt of WD40 around the slide can help. Give it a try - it costs nowt!