Evening all. Long time since my last visit here...
I'm hoping someone will recognise these symptoms and save me a job diagnosing the problem. I have a Suzuki GSX600F on an M plate and recently when I've gone to work on it (I say recently - twice last year and today as the problem puts me off) it's fine for the 20 or so mile journey to work, nice and responsive, plenty of power, and for about half way home. Suddenly it feels like it's lost a cylinder or something - the revs go growly and it's slow to pick up, and very down on power. I tried switching to prime (suspecting a vacuum fault) but no difference.
Last year it was two consecutive days, and it was fine the morning after it did this, then went weird on the way home again.
Ring any bells for anyone? I do very few miles so it's possible it's gunged up, but why would it do it around the same point three times and then be ok the next day?