Put new mains in and seals, wasnt aware of moving anything gearbox wise but now rebuilt wont engage to select neutral. The shaft holding the gear selector drum one with the shaped grooves did cone out so I placed it back in maybe that has caused it.

Any advice truly welcome.

Thanks in advance

Nick

it is always best to make sure everything is working as you go through each stage , it is necessary for the shafts to be turned for the gears to locate , i think you need to dismantle until you find the problem , also tightening the casings back up if some things out of place it could cause damage so always make sure all shafts turn nicely whilst fastening back up ,, you may need to tap the crank to free tension through the bearings to free it

I am not a beta expert but I would start by making sure that you have correctly installed the shift shaft and the springs that position the levers and pawls that engage with the shift drum. These can usually be accessed inside the clutch housing without splitting the engine cases.

I recently got a great deal on a Yamaha because it would not shift. Found that one of the small levers had a broken tab. Replaced that and it worked perfectly. $700 price discount for a $15 fix.

Usually you leave the selector in neutral while assembling to make sure everything is free and clear. Good luck, I`m sure you will get it. Just don`t tear the center case gasket.

Thanks again will strip down again when I have time.