On a new to me '74 Triumph 500 the kick start lever falls down when I'm accelerating. On a Norton that would mean that the layshaft bearing is toast. Is the Triumph the same ? If so, how hard is it to get the guts out of the gearbox ?

Thanks

Greg

'70 Norton Commando
'82 Honda GL500
'75 Honda Goldwing
'72 Bultaco Sherpa T
'74 Triumph Daytona

The 350/500 Triumph layshaft and kickstarter shaft arrangement is very similar to the Commando gearbox (unlike the 650/750 twins) so it could be caused by the same problem?

Working on the Triumph gearbox should be quite straightforward.
Triumph workshop manuals here: http://www.classicbike.biz/Triumph/Repair/Repair.htm