Pull your plug.. Check the colour. Any excess sooting around the tail pipe too ??

As a side note....I had an R1 from new. Ran it in exactly as I should (painfull few days of self restraint) and by ten thousand miles it was burning a litre in a thousand miles. Yamaha technical said it was acceptable consumption for that engine.
I had the motor rebuilt and tuned by Bob Farnham (famed for building endurance race motors for Yam) who told me Fully synth is no good for that motor....use a good semi. After that no oil top up between services, sold the bike with 27k on it. I also had a Thunderace that used oil......but Honda's and Ducati's that didn't. Maybe it's just a Yam thing !!!!!

Ted, the plug is about right, perhaps a touch lean. Exhaust has no excessive soot. Would you think using loads of carb cleaner in the oil cleaner might help to clean things up?

Interesting thought about oil. Its becoming a confusing issue. Had a similar situation with mk5 tranny. Ran it on fully synth for a while and it sounded like a bag of nails and used some oil. On the ford oil which was semi, it purred along and didn't use any.

So is it Silkolene comp 4 or Super 4? The bloke from the shop who does seem half competent always says comp4?

Early Thunderace had a problem with oil consumption, i have latest model and its no issue. I use semisynth as recomended for this engine, R1 had problems with oil blow out from crankcase breather in high rpm.