79 659 shift lever stiff

 I was wondering if someone migtht know something about the shift
lever? I just took my bike out (It's running great) and I discovered
that when I press the shifter foot lever it does not want to spring
back to center position or does so very slugishly and does not come
back all the way. I thought at first it was a trans problem but when I
got it home I saw that it was stiff in coming back. I lubed it (the
shaft) as much as I could but it didn't help. The lever will return
from an upward just fine but not when I push it down seems a bit
stiff. Was wondering what someone might think will cause this. Other
than that the trans works fine but I have to play around using my toe
to downshift always having to shlightly pull the lever upo with my
toe. Up shifting is no problem just once I'm in a higher gear it is
hard to get it back. I hope this is not a mojor issue and was
wondering if someone have had any experience with this kind of thing.
Thanks BTW. I just replaced the stator and have jamed a rag between
the drive sproket while i have the bike in gear in order to get the
nut loos that holds the stator on. I cann't immaginge this would have
caused the problem but who knows. Are there any reurn springs that are
easy to get to or some lub points I am misssing. I took the left side
cover off and sprayed WD40 in as far as I could but all I get is still
a stiff feeling shift lever that tries to return but will not come all
the way back with any zest....but like i said, an upward pull of the
shift lever seems very normal. Hope someone can direct me. Thansk for
any help in solving this .........Bill

 Bill wrote:

The shift mechanism is quite involved. If you want to look at diagrams, go to
www.bikebandit.com
and click on OEM Parts > Yamaha > 1979 > XS650 > then look at Shifter 1 and
Shifter 2.

The shifter shaft has to go through the engine to make the shifter operate
from the wrong side, since
the DOT mandated lefthand shifting and righthand braking and Japanese
motorcycles were often inspired by Triumphs and BSA's that had righthand
shifitng and lefthand braking.

Your shifter shaft might be bent slightly. You can see the hairpin return
spring on the left side of the engine.

Then the shifter turns a ratcheting device that turns the shifter drum by
grabbing one of several steel pins in a cage.

The shifter drum is the strange looking cylindrical device with odd grooves
in it. Pegs in the ends of the three shifter forks follow the grooves in the
shifter drum (#1) and the shifter forks slide gears sideways to cause the
dogs on the sides of the gears to engage slots in the adjacent gears.

You may notice the detent mechanism that holds the shifter drum in the
position it was left in the last time you shifted gears. It's possible that
the detent mechanism is sticking or that the shifter drum isn't rotating
freely in the engine cases.

The detent mechanism can be removed from outside the engine by removing #19
and you can see the gizmo with the steel pins in it if you pull off the
clutch cover.

The shifter forks and the shifter drum are probably inacessable without
taking the engine all apart, but
it looks like there is some sort of plug on the end of the shifter drum that
might be visible from the left side.

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