Tranny Gearbox issues

[Kiwi 1]

Hi all, new to this but looking for some advice with my 03 Transalp. It's done quite high kms, like 125k and has been good to this point. Currently using it as a courier bike so 1st, 2nd and 3rd get a good workout. It's beginning to kick back out of 2nd into neutral occasionally on the 1st 2nd upchange, which is a worry. It also (less often) will drop out of 3rd back to 2nd when given a good hard wind out. The first second problem can be alleviated by being very deliberate on the change and holding upward pressure on the gearlever until the clutch is fully out. No problems going down the box.
Is this a selector problem or more serious? Anybody had similar experiences? All help appreciated!
Cheers

[StumpyFingers]

Welcome to the site.
I have no idea what the problem could be, but I am sure someone who will have an idea will be along soon.

[AlanH]

If it starts jumping out of second under power or goes 'clunk clunk...' and feels like the chain is skipping, you've got serious gearbox issues - like worn dogs that will kick the cogs sideways and bend or break a selector arm.

If it's just a bit hit or miss on selection, you may find that it is just a weakening spring on the roller that rides on a cam on the end of the selector drum holding it in gear.

I've had both these issues on various high mileage Hondas - the second one is easiest to fix.

[Kakugo]

Hi Kiwi. Similar problems on Hondas are usually down to worn selector arms and/or weakened roller springs. The fix invariably involves opening up the engine.