Not always, but sometimes when I change up from 1st to 2nd, 2nd does not engage. This is entirely random, and most of the time this does not happen. If I disengage the the clutch when this happens, select 1st and then select 2nd again it engages straight away. Any suggestions as to what might be causing this? I have adjusted the camplate plunger so that only two threads are showing beneath the lock nut and that has improved things ( before adjustment there was about 4/5 threads showing). Doing this has made the change much more reliable but still sometimes 2nd will not engage unless I change down to first and change up again. When 2nd does not engage the gear shift pedal feels as if it is jambed.