Scooterotica

SIL GP200 engine, sometimes jumping out of third gear and very difficultot get into 4th and as soon as it's in 4th you need to keep force on the handlebars or it will jump out continiously. The cables are routed correctly and allow enough movement, the swivel is mounted correctlt on the engine casing and as far as I can tell the gear shift arm looks to be in the correct position as well (pointing at half past five when looking down when in neutral).

If you have rubber gaitors on the cables they can cause it to jump out of gear.

1st gear cable to tight try slacken it off or worn selector.

Ok, thanks for the suggestions, will check the above out...

Slip the tie bar off the selector arm then remove the circlip on the swivel and lift off the post, then turn the twist grip towards 4 th. If it binds it may be the clutch cable trapping in the headset, easily done with some of the thicker nylon lined outers. If that's ok then it may be in the gearbox so reconnect the linkages, jack the back end up and turn the wheel whilst turning the twist grip through the gears.