Sticky throttle

[shinyribs]

I cant get rid of it. I have new cables lubed every which way and I even lubed the throttle fork lifter rod and every moving piece i could find. I even went as far as polishing the inside of the throttle control where the sleeve rotates and even put some real thin grease in there and where the sleeve rotates on the handle bar. Every moving piece of my throttle assembly is either new,polished smooth or lubed. When the bike is off the throttle snaps back perfectly, 100% of the time. But as soon as I start the engine it hangs, 100% of the time. Any ideas? I'm completely out of 'em,myself?

[pat english]

thats weird..is there alot of bend in the cables?are they stock length cables with clip ons or clubmans?

[shinyribs]

Yup. Stock replacement cables from Vintage with clubmans. They are routed kinda funky,it makes them sotra hang out, but there are no bad bends. I can take off the heavy return spring and it will snap shut perfect with just the curly spring that wraps around the lifter rod. I can turn the bars in every direction and it snaps back,too. Just so long as the engine is off. Excessive vacuum pulling on worn out throttle slides?

[pat english]

that was my best guess..i have no idea on the vacuum thingy..

[shinyribs]

can i lube my slides? So #%&# irritating. I might as well throw all the springs off and have a super easy throttle to twist cuz i've been fiddling with this for close to 10k miles now. For real.

[pat english]

maybe add another small spring?

[welard]

Hey shinyribs, wha did this end up being?? I'm getting the odd sticky throttle now myself. Although not sticky, it just takes a while say about 4-5 seconds to return when the throttle is twisted off. Scary on the gear changes. I'm thinking mine may be a lazy spring. Just interested to see if you found what was causing your issue? Cheers Pete

[cblover]

I had the same problem recently, changed the cables and lubed every moving pieces, but problem still there. Tried check the carb butterfly and guess what it was the culprit. Butterfly number 1 has a little bent on it. After replacing it, it went back to its smooth operation.  

[shinyribs]

Actually, I never did figure that one out. If I ran with the super strong spring that the bike was built with it did fine. I guess they knew what was needed when they put that on there. I just never liked that stiff of a throttle and just learned to close the throttle by hand.

[welard]

Thanks guys, its weird, because when the bike is not running or warming up it snaps back no problem. Once its at operating temperature it hangs.....actually revs higher when the clutch is pulled in...makes for rough gear changes and I'm sure the clutch isn't going to tolerate that for long.

Anyway, the magic number seems to be 3,000 rpm. If I short shift thus keeping revs below 3,000 rpm then its ok, as soon as it goes above 3,000 and I pull the clutch it revs up to about 4,000 for 5 to 10 seconds and then slowly revs down to idle.

So, I'm thinking it may be a vacuum leak issue or an auto timing advance issue......hoping someone has some knowledge and can tell me how I can tell which, if any of these it may be.

Cheers

Pete  

[Truck]

Might just be simple heat expansion. When the bike is cold everything is loose and the return spring had plenty of pull. But when the bike warms up things expand, tolerances shrink and things might be to tight for the spring to snap back.

[Re-run]

I was thinking something like this too.

Does the stick stop as soon as the engine is off? Or does it need to cool some? Only things I can come up with would be something with vacuum though I don't see how, unless the throttle does not control the flaps like it does on my v45.

If it sticks for a bit, I could see heat causing something to bind then, most likely the rod the flaps bolt to.

[shinyribs]

Well, mine was that way:snapped shut fine not running, but was sticky any other time. I always closed it manually so I don't know if it worsened with heat. never took that chance.

I always thought it might have been worn slides. The slides on my '76 were visually worn and didn't move (by hand) in the bores as well as the nearly pristine ones that were in my '74. The '74 had no problems closing at all without the stock way-too-stiff spring. And it had super long cables too. 10" over stock IIRC.

[gkmaia]

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