Hi all - I recently had a problem with my bike in that the gear selector refused to work and this ended up with the case being split. I found the secondary 3rd Gear cog to have lost a tooth and this looked like it was the culprit. I've bought a replacement cog plus another that looked a bit shabby and am ready to put it all back together. My question is 'on reassembly' is it a case of putting the selector forks on at a particular point or at a particular setting? What I'm getting at here is I don't want to find 4th when trying to get 1st!!!! Does anyone have any tips or can they point me in the direction for any illustrative diagrams or manual??? All help greatly appreciated!

You always put in back in neutral.

Neutral

Thanks for the replies - get out of one problem and fell in to another..... Replaced the worn cogs, found neutral and started to put it all back together but on trying to go through the gears (by hand) I can't seem to get passed 3rd. It's as if there's no more cogs in the box and I'm in top gear. All I can think is that I had found a false neutral for a starting point and somehow started to far 'round' the shift drum. Any ideas? And while I'm here - just so I'm not going mad - it is 1 down 4 up right?

That transmission will not shift partially assembled. Neutral is located on the shift drum by the spring tension roller. Did you check too make sure the forks are straight? You can put the forks back to back on the same shaft to check. Good luck.

ANd it has 6 gears.

Yep the forks and straight; I'll be taking the shift drum off again for a closer inspection tonight - is there a mark or anything on it that you use to line up with spring tension roller? Obviously it ain't rocket science but sleep deprivation from to young children plus a manic puppy makes everything appear more complicated than it should!

The shift drum has a seven point star shape. It is the one without the point.

Thanks so far for all the help - much appreciated!!! Right, I've stripped and rebuilt twice following the exploded diagrams, info from on here, your help and Jim Snell youtube clips. Neutral, 1st and 2nd are perfect but finding 3rd, 4th, 5th and 6th (who'd have thought 6 eh!? Lol) on the bench is not happening. Could this be down to eccentric adjustment 'or' is this simply because the engine and gear set needs to be running to get in to these gears?? First time I've done anything like this (up till now pumping a tyre was technical) so your on going help truly is appreciated!!!

You may need to turn the gears to fully mesh them, a bit like when you would rock the bike back and to when it is stuck in 6th.

Watch these videos http://youtu.be/XgKLrVBn2O8 helped me do a complete rebuild hope they help

Yeah, found those and like you said followed them and now I'm about set to put the case back together. For what's it worth to any other newbie attempting a case split I reckon this is do'able as long as your methodical. What I've found whilst checking the shift drum, selector forks and gears is that without the case together and no clutch there is a tendency for the selectors to 'push' the shift drum out which I turn halts any gear change which, if your not checking this, it can make you scratch your head a bit as to why it ain't shifting. Equally when going up the gears you got to ensure the selector wheel 'holes' line up with the required cog or it won't mesh leaving you wandering why it won't click in to place. The the case back together the selector forks spindles will press in to the case holding them in place so when pressures exerted they can't push out and this will be the same for the shift drum spindle so it shouldn't have the space to move out exposing the spring loaded guides stopping the whole lot from functioning. Thank you so much to all who've responded!!!