Topic: ANOTHER Throttle cable question on a 78 550K...

[Kixx007]

My throttle is REALLY stiff.  I bought the bike a few weeks ago, and this is the way it was.  When I got  it home, I disassembled the grip, cleaned the bar up, cleaned the grip out, and reinstalled it. It turned freely on the bar.  I then disconnected the cables at the carbs, and lubed them with my cable luber.  They also moved freely, when I reinstalled them, I noticed no difference.  The bike also seems to rev to about 5000 RPM's when you start it cold, with the choke on, this again, does not seem right.  Anyone got any ideas?  I temporarily disconnected the push cable and that seemed to help some, but its still kind of stiff.  Thanks for any help.......

[74cb750]

hi. Well I had the same thing. Solution was the casings were not on the bar correctly, ie, the pin on the bottom casing (with the starter button) was off center. Also, your return spring could be in need of replacemnet. A ?, are you turning the throttle, in the casings, towards you before you tighten the screws?  michel

[Robert]

I temporarily disconnected the push cable and that seemed to help some, but its still kind of stiff.

Maybe caused by one or more problems like:

(Cable related)
Throttle free play correct? (push/pull cable fight each other, too much tension)
Routing correct?
Cable damaged (damaged or not proper routed cable behave different under load, as too much friction is created in the cable)

(carb related)
throttle shaft/linkage can't move freely. Corrosion, fouling.
throttle valve can't move freely because of dirt. (unlikely)


Aditionally (the 5000 rpm problem), the fast idle seems to be misadjusted (or hanging?). in most older carbs, there's an adjustable screw which rides an excentric cam that is moved with the choke lever. Try to find something like this. In other cases it's an adjustment arm that has to be bent.

[Kixx007]

Well I got the stiffness worked out, and I removed the push cable (it was the wrong length). 

I adjusted the screw on the choke cam, everything moves freely, so I dont think its sticking.. It still Idles high, untill I push the choke halfway in, Maybe this is normal?