Giving me the right hump!!

[sydduckett]

Just finished my RB20 project ready to go and the gears keep either slipping or not engaging. Im not sure why this is happening but i did have similar issues before in its previous Li150 guise. Problem is either that get the gears set up get 50 yards down the road and they have slipped or they are complete mush and cant even get it in first even with my arm at a dodgy angle and standing over it. Have not even been ablke to find 4th at all. the clutch whilst tight appears to work fine.

Things i have done to cure it:

new inners and friction free outers
new MB cable block
Replaced brass wheel in headset as prev one worn a bit

Next plan is to weld the inner rod to the handle outer at the handlbar end to remove slop (as per sticky manual p141), there is a bit of play and welding should cure this but whether that also sorts the gear selection issue im not sure.

Its doing my head in big time, I dont want to pull out the gearbox unless i really have to.

Any ideas of what the prob might be greatly appreciated.

Sef

[bristolmod]

worryingly a mate has similar problems although he has great difficulty finding neutral (the gears all work OK when the bike is on the move)

We've traced it to the gear box selecter arm bush (where the selecter arm passes thru the crankcase near the rear shocker mounting)- you can see the arm moving backwards and forwards when he tries to find neutral as the bush is so worn.

This will invove a full gearbox strip down and bush renewal when I can be arsed to do it for him.

Just an idea

Chris

[bristolmod]

just had a thought.............its not one/ both of the gear outers popping out of their slots at the headset is it?

C

[dapper]

What he said^^^^^

[Bilko]

^^^^^^^^^^
Same symptoms.
Happened to me!

[sydduckett]

No I replaced the brass disc that holds both cables and that is now nice and tight. I dont expect every gear to slip in ala vespa, but its either like stiring a bucket of coal or just really sloppy depending on how tight/ loose i make the adjustments.

This does need to be sorted and quick as iv been working on the is scoot for nearly 6 months and missed the London-southend ride out. Was gutted spent from 9 - 10.30 with some mates trying to sort it only to fail miserably and then to watch them say sorry and head off to the ride out while i stood there cursing.....

Im trying to work this out in logical order, with removal of gearbox the last and final result although having said that if i knew it was defiantley the bushes id have the side off in a jiffy.

so suggestions for order of possible causes and which ones to try first very welcome.....

As an aside the 5 mins or so i had on her, the engine felt very boggy and tight, i wasnt giving it much but im presuming this is coz im running her on 4% to start with?

Sef

[sydduckett]

Bilko,
and you fixed it how? Also what was your RB like when you first took it out, mine felt tighter than a virgins chuff and was very boggy. Very disapointing but im hoping/guessing this is to be expected due to the newness of the kit and the higher oil ratio that iv been advised to use whilst running in?

Syd

[Bilko]

I had simular problems with gear selection on a different engine. (not a RB20) It was due to the outers not being sat right in the headset clamp. (That's what I was pointing to, the post by bristol mod)

[sydduckett]

Bloody ell, thought you were to to say "what you need to do is.............."...lol

[Bilko]

Sorry.