Had a problem that just came up on my last few rides.
It's like the gear just doesn't want to shift, like it's locked up or stuck. After two or three tries, it finally shifts. No noisy clunks or grinding or anything. I'm engaging the clutch fully and giving the shifter plenty of umph with my foot, so that's not it. Downshifts are fine.
So far, it seems to be only happening on shifts betwen 2nd & 3rd, and 3rd to 4th. It shifts to first from standing still and into second just fine.
It doesn't happen every time, but most times.
Any ideas?