Gear changing issues

[Steve M]

Hello clever people. My Z1 based sprint bike developed a gear changing issue while racing at Manston last weekend. It started by missing 3rd gear but would go in eventually if I gave it a very brisk boot, but as I did a few more runs it got worse and now It wont readily go into second, either at low or high engine load. I'm suspecting selector forks but have also heard that there is a relevant spring that may have failed. Having not had the engine apart for 30 years I am struggling to remember what you can get to behind the clutch but my vague recollection is not very much at all. Any suggestions would be welcome before I embark on a full strip down.

[gray]

sounds like a selector fork ( sorry) if it was one of the pawl springs or return spring it might affect all gears

[zed1015]

It's more likely a bent selector fork unless the actual selector mech behind the trans cover is faulty.
A broken gear lever return spring would affect all the gears.
To access any of these there no need to remove the clutch cover but the clutch can't be removed without splitting the cases anyway..
The selector forks are accessed through the sump after removing the trans cover which allows the shaft they run on to be slide out.

[Steve M]

Thanks guys, sounds like my original suspicion is correct but pleased to hear that I can get to everything from the bottom without a full strip and crank case split.