dead again
 

riding home last night....took off from the trafic lights and gearbox jumped out of gear to a rerrible sound of crunching .....every time gave it the throttle it jumped out of gear to awful sounds.....up at five to check chain and sprockets hoping it was something simple....no luck.....looks and sounded internal so back to square one and engine out and dtrip and inspect....gutted....will report back....:thumbdown:

Sorry to hear that. Krunching is never good....

Before you start going crazy assuming the gearbox is toast and tearing your engine apart, check out the selector mechanism first...

And is your clutch working okay too ???

yeah clutch working but I ll start with that and if its ok I pull the engine and do the gearbox...no warnings or noises just sudden....just been out to check the clutch and I can put it in gear but when I pull the cable its not disengaging....maybe a clutch problem ?

Thank goodness for that! :thumbup1:

Could have been terminal. :thumbdown:

Update....not good...removed engine and stripped gearbox to find the selector fork for second gear worn....worn one side flat so checked the second gear which is at the end of the gearbox shaft closest to the crankcase casing...

On inspection noticed the gear might have been put in 180 degrees out....when put in the other way it fouls against the casing?...gearbox is assembled per the manual with the spacer in place ,cant see if there should be a shim there but the manual does say "make sure all shims are in place ".......

the selector fork was ground away because the gear was holding it the wrong place and that's why it rode for 1000kms before it stopped doing its job.....when I assemble the gears the way it came aprt it works fine but when the gear is put 180 it grinds and becomes notchy....

Any inupt welcome as I cant reassemble till I find the problem....I ll check the bearing is fully seated....

I ll check again tonight and see if my mates can source the problem....

Initially thought I may have put the gear in 180 degrees out but wont fit if you put it in wrong....fork does not appear to be bent so cant figure out why it has ground half of the selector fork lower leg away.....don't know if its possible to bend one if your hard on selecting a gear.....anyhoo....have replaced fork selector and will have the gears undercut by a local engineering firm just to make sure then rebuild the engine and hope it doesn't happen again....pissed off I have not been able to identify the issue......

Can you post some pics of what is happening? To grind the fork away something has to be either pushing on it at all times which they shouldn't. The forks should be sitting with some gaps on each sit, just hitting when actually changing gears, then back to being free from hard contact. It is possible to bend a fork and then it will always be pushing on a gear when it shouldn't. Compare the new fork to the old and see if there is a difference. Does the drum have any wear marks or any of the guide shafts ect. straight.

Shifting without using the clutch can bend forks same with excessive force when jamming through gear changes.

It could be that you are over shifting. There should be a limiter mechanism. Maybe this is not working or installed incorrectly.

I reckon you've missed out a shim, mate, or put one in the wrong place.

The fork was well ground away.....cant understand why and there are no shims according to the parts book or rebuild manual.....I ll put the cases back together and check the operation again....I ll take a photo and see if I can put it up...