Buttery smooth throttle cable action?

[Qaxe]

I've watched a couple videos with fellas who walk up to their >stock< CB750K, and "blip" the throttle with just their index finger and thumb... like it's a friggin' race bike. How are they doing that?

I have brand new, stock K6 cables (2 days old) on freshly cleaned and tuned 1976 KeiHin 086A Carburetors. Stock K6 bars. Cables aren't tight or too long. Throttle turns and returns like every other CB750 I've had (this is my 8th). It's good, but I certainly can't twist it with 2 fingers.

My grips are...Emgo...Jackhammer grips. They are 1/8" away from the switch housing, so there's no drag there. My return spring on the carbs is of unknown age, but it's very clean, no rust.

I never had any expectation about this sort of thing, I just saw these other guys and was baffled by the smoothness.

 

[brettp]

Do they have stock carbs? And stock cables and stock handlebars? All of that matters.
I put drag bars on mine and the cables had binding. I rerouted them and it helped. I eventually rewired new switches on the bars and needed an aftermarket housing; which I found. My throttle returns but it drags somewhere. For butter smooth operation, your cables need zero binding and the housing needs to be lubricated.

 

[Qaxe]

Sorry, yeah stock carbs, stock cables, stock bars.
Cables routed around frame neck, past the ignition coils, and through a triangular hole behind the ig.coils. I think the routing sucks personally, but I don't know another way. I have WD40, but will look into a better option for cable grease.

 

[brettp]

There are a lot options for lubrication but I'm no expert. I don't know the difference between a silicone lubricant and any other. I do think they make lubricant for cables.

 

[Qaxe]

Feeling a bit foolish for assuming that "new cables" meant the same as "lubed cables", but now that you mention it...

Did a little search and "PJ1 cable lube" is ... $18?! Holy carps. Great, just what I needed. Another can of overpriced something-or-other that only does 1 job.

But apparently, the silicone lube that I already have in the shed, will work nicely. So thanks for the brain power. I often need at least 2 brains to get things done.

 

[Qaxe]

Okay! Silcone spray lube helped a ton. It's not race bike slippery, but much better.

 

[Qaxe]

I must not understand throttle push cables. ...or I have another problem. It's me or the bike.
After lubing up the cables, I went riding. My throttle began sticking when released, and I had to manually twist back to let off the gas. When I twisted back to ease off the throttle, I could feel a sticking "chunk" in there on my hand. I checked inside the throttle / start switch housing, in case I installed my inner throttle tube wrong, but it was fine. So I loosened the return cable at the handlebars until the "chunk" (sticking feeling) went away. Now my return cable works, but it's all loosey-goosey.

I'd like to point out, that a month ago my return cable snapped, and it only had about 200miles on it. That's the reason I ended up putting on new cables in the first place.

I wonder if that big spring on the carburetor bank is too old to be doing its job correctly. It's "clean" but that doesn't always mean good. What is this bike trying to tell me, anyway?

 

[brettp]

I am willing to entertain the fact I could be wrong, but....Your return cable is "activated" by that carb spring, and simply returns your throttle tube to the start position. If that cable snapped early, I would be inspecting the connection at the carb.
Where did the last one snap?

 

[dirtdigger]

The return cable is there just as a failsafe to make sure the throttle doesnt stick open, it should be slightly slack so it doesnt interfere with the throttle movement.

 

[Qaxe]

Thanks. That makes sense.

Note to self: we're not stringing a banjo here...

 

[pickleknuckles]

Okay! Silcone spray lube helped a ton. It's not race bike slippery, but much better.

Sounds like you got it figured out but I figured I'd add my two cents for others.
I've got the superbike style bars on my K4 w/a CycleX/Barnett cable. It would drag w the front turned either direction. Keeping the return cable minimally slack, I loosened the main cable just a hair at the carb and it no longer drags at all. No additional cable lube needed and there's no additional play in the throttle twist.
Like you said, "we're not stringing a banjo here..."