f2 jumps out of 5th

[westfieldandy]

my f2 jumps out of 5th,  any idea's,   can i lift bottom engine casing off leaving crank and everything in top half, so i can check transmission?

[SteveD CB500K0]

Hello Andy. Long time since we've spoken (North Weald about 2/3 years ago - you were there on your Seeley)

Don't know the answer I'm afraid but welcome back anyway.

Steve

[matthewmosse]

can do that on the cb550 motors - not played with a 750 though

[Spitfire]

Hi Andy, the answer is yes, drop the engine out, turn it upside down and take the bottom crankcase cover off this will give you access to the selecters and the drum. Haven't done it in years though the last time was the morning before my mate was setting off on a trip to France, had to fix it in his back garden !
Remove the engine side covers (generator, clutch, gearchange), points cover, points plate, gearchange mechanism. In fact just follow the engine stripdown but ignore anything to do with the top end.
Make sure that you get all the crancase bolts out, including the top ones.

Cheers

Den.

[Bryanj]

Jumping 5th is unusal its usualy 2nd or 3rd. Start by removing the gearchange mechanism cover and making sure the detentsrring(s) are in good order----they have to come off to pulll the case anywayso its not lost time

[steff750]

  i had this problem years ago ,after quickly rebuilding a k4 engine (to use in my k0 that had camshaft failure)i left out a bearing set ring its a half circlip that locates the gearbox bearings in the engine cases, it could be the same part bryanj mentioned ? it work ok for a while then started jumping out of fifth then no fifth at all ,only four gears lol, (i rode it like this all summer until i fixed my original engine) it only came too light after i dismantled the k4, as spitfire says the job can be done upside down no poblem, you might have too wiggle the cases a bit to split them

[Yoshi823]

When about to invert the engine don't forget to have drained the oil before removing the engine.

The half-circip stops any sideways movement of the gear cluster shaft.It is easily mislaid and forgotten about and has been known to break.