Aprilia SX 125 (Rotax 122) Gearbox Issues

Miless · L Plate Warrior Joined: 18 Apr 2017 Karma :

Hey, I am having the weirdest issue with my gearbox. So, I rebuilt my engine during winter, and I got it all back together and running about two months ago. Everything has been running PERFECTLY up until now. This all happened overnight, but basically, the morning this happened I was riding to school and I realized that I was not able to shift into third. First and second gear both engaged perfectly fine, but it just wouldn't switch into third. The lever was budging, but it wasn't clicking. It was just kind of going up but not engaging the gear. After some experimenting, I managed to get into third but only when driving at around 20kph (very slowly), but it was practically impossible to get into fourth gear. After some further investigation, I managed to bump start the bike into fourth gear, and it ran perfectly fine. I could switch into fifth and sixth without any problems, and the gears ran just as smoothly as they usually do, however, when I shifted down to second gear again the same issue arised where I was unable to progress into third gear again. The weirdest thing is that as I mentioned, this happened overnight. The night before when I drove home from my girlfriend's house the bike was running perfectly fine.

I have tried changing the gearbox oil, but I really cannot come up with any logical explanation as to why this is happening. I am not very keen on ripping the engine apart again, so any help is greatly appreciated so that I at least know where to look. Thanks for your time!

Miles

bypass2 · Spanner Monkey Joined: 12 Sep 2013 Karma :

does the gear lever nut/bolt need tightning on the gear box shaft. linkage

Miless · L Plate Warrior Joined: 18 Apr 2017 Karma :

Miless · L Plate Warrior Joined: 18 Apr 2017 Karma :

Not sure if bumping posts is against the rules, if it is, I am sorry, but... bump... I really have no clue what to do here.

Miless · L Plate Warrior Joined: 18 Apr 2017 Karma :

UPDATE!!: Took the clutch cover off and rebuilt the basics and put the cover back on, now different gears are acting up. Third gear is now easily accessible... Anyways nothing is really solved, BUT, I did find a clue. The gear lever shaft has play in it, and I am able to wiggle it out and in maybe a centimeter or so when the clutch cover is ON. I am 99% sure that it is not supposed to that way. Can someone confirm this and what could possibly be the cause of it?