G: Gearbox (Twin) Transmission pops out

[Denny653]

My '52 Black Shadow is now running and with the help of a Godet starter, it starts right up. I took the bike out a week ago or so. I was riding it easy as the engine only has about 150 miles on it. On back roads it popped out of third. When I got on the highway to return to the shop, it popped out of third and fourth. This happened at low rpm as I didn't want to beat on the engine. Ideas?

 

[vibrac]

Reset the gearbox inside the cover something moved while fitting the starter it only needs a fraction to throw it out

 

[bmetcalf]

That adjustment can be fiddly, so have patience!

 

[erik]

The way of the gear lever is to short.Remove the right ear of G61 and move G61 on the shaft more to the left.But only a little bit.And like Bruce above says with patiece.Regards erik

 

[vince998]

Hi Denny, If you can feel (or hear when stationary) a light "click" when selecting gears, the detent plunger is enganging in the camplate slots and the gears should be in. If the gear still disengages, you could be slightly over-selecting, and going into a false neutral between the gears. I had the same last week from 1st to 2nd, and 2nd to 3rd. Stripping the gearbox cover revealed the selector stop plate tang for changing up (or down on British bikes , i mean the forward tang to the right of the stop plate) had bent to the extent that it was touching the kickstart quadrant. After removal and bending back (by eye) so that the rear and forward tang where 90^degrees to the plate, everything now good. To set the stop plate, i also do this by eye so that the gearchange mechanism has equal movement between the tangs and comes to rest right in the middle of these. If the resting position varies, also check the return leaf springs in the complete assembly!

 

[Denny653]

Thank you to all who have responded! I will get back to it in a couple of weeks. I'll post my result.
The people whom I have met in the motorcycle community in the last 40+ years are the best.

 

[CarlHungness]

That adjustment can be fiddly, so have patience!

So true. I re-adjusted mine over the winter and it seems as though I got it right this time, but I'd just as soon shovel snow as to fiddle with the thing.