Topic: 1977 cb550k - throttle and choke

[Can550]

When I decelerate, grip comes back all of it but then I can't pull the choke unless twist grip (acceleration direction) there's a bit of play in grip without any spring tension.

Is it normal as I don't recall this being the case with my 1976 cb550k

Appreciate help and correcting it or to know if it's the way it's to be.


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[robvangulik]

You can't pull the choke without twisting the throttle?
Did you take the tank off (done in an instant) and look under there if cables are binding or things get hooked up?

[Stev-o]

Is it normal as I don't recall this being the case with my 1976 cb550k
 

No, it is not normal.  Did you try rerouting your cables like I suggested in that other thread?   [why start a new thread, seems this is related]

Doesnt the '76 550K have the choke on the carbs?

[TwoTired]

The pd carbs have a fast idle cam and a step between off and applied choke. This is where the fast idle adjuster screw rides on it.  The adjuster screw is lifted when the throttle is twisted, so the cam can easily move with choke operation.
Check the cam for smoothness, perhaps add some grease where the screw makes contact, if you find twisting the throttle too much of a burden during choke application.

May also help to reduce throttle return spring tension rate.

Also, you may have adjusted fast idle too high.  The longer screw length in that case may cause the cam to interfere with cam contact as the choke is moved.

Your 76 did not have a fast idle cam.  You had to hold the throttle open during warm up and choke operation.

Cheers,

[eigenvector]

Yeah, what they said - check your cable routing.  The choke cable isn't even on the same side as the throttle cables - so it shouldn't be binding on anything.

What I have found on mine at least is that the choke cable is overstressed - the choke butterflies are a little too stiff and the pull doesn't have good mechanical leverage.

Is it possible the carb assembly is slightly twisted and opening the throttle binds the choke butterflies or releases them (some variation of that)?

[Can550]

Thanks everyone for all valuable input.

Got it fixed. The reason found was simple but I pulled the carbs out to see. It was loose set screw and locknut as shown in following photo number 2 and 3. (Throttle where the cables attach).

Since set (stub) screw was loose, it was moving a bit till the raised part touched the fast idle screw. Tightened it and all set. Will put the carbs tomorrow and test start it.




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