81 Seca weak up-shift

Any ideas on how to rectify a hard upshift problem with a 1981 SECA 750? It sounds/feels fine going into first but takes a hard toe-up to reach 2nd - getting past neutral is difficult. I have yet to try any other gears - just out of storage - have just changed the oil with non-synthetic 10W-40.
...The bike has 20,000 km/s on it, clutch seems ok...

Any suggestions would really help, thanx.

TD

 

You might be suffering with the dreaded starter chain tensioner syndrome.
The tensioner literally dries out and cracks into pieces that then rain down upon your transmission, usually resulting in a locked tranny that won't shift out of first or neutral. I'm thinking you have a smaller than usual piece jamming up your shifting linkage. It is a PITA to clean out the pieces. There is a fellow on the Chat forum that just performed open heart surgery on his bike to remove the pieces from his tranny, you may wish to take a look. Good photos in that thread too.
Other than that, you may have a bent selector fork. I'm not a wiz with these things but I'm sure one of the more educated fellows will be along to either debunk me or confirm my suspicions

 

Thanks again Robert!