Choke not functioning?

[VK]

My choke appears to do nothing at all.  Everything that is visible externally moves as should be, but there seems to be no effect on how the bike runs, whether the engine be cold or warm.  (The engine idles the same no matter where the choke is set.)  The carbs were cleaned by a shop 1.5 years ago, but I have not attempted a cleaning myself.  Is it possible something internal to the carbs is gunked up and causing the choke to be ineffectual?  The bike can be a challenge (to put modestly) to start in cool weather, and it would be nice if there were some easy corrective measures I could take.  Any advice out there?

Thanks!  VK

[Lucky]

I'm assuming it's an 82... I've never had an 83 give me an ounce of trouble as far as the choke goes.

the 82's have some very small passages, and one is for the choke.  sometimes when these get clogged up they are a bear to open back up.  One of my own carbs has never choked right, and i've dipped it a total of 3 times now, the last time in the ultra sonic cleaner.  this passage isn't one you can physicly reach either, although it seems to pass air from a compressor ok.

before I switched out this carb (which is one of my favorites) I just pumped the throttle a couple of times to fire the accelerators, & set my throttle lock at 1800 for 30-45 seconds or so.  before that I used the adjuster on the throttle cable (by the grip)

bottom line is that cleaning may or may not help...

--Lucky

[Blake]

One thing you might want to check is the carb overflow tubes.  I used to have a problem with my choke getting caught on the overflow tubes the first time i opened it up, and then never would go back..screwed up my mind for the longest time until i went and looked at the choke mechanism on the carb while i flipped the choke.  just some bending and repositioning helped it out.




just a thought.



Blake

[QBS]

Before you get too concerned, verify that the choke is indeed properly connected and that its actuation cable is properly adjusted.  If either of these items are not right the choke (actually the enrichment circuit) won't be activated enough to get its' job.  I think you can see the choke cable and its carb attachment point by just peering under the left side of the tank in between the carbs.  Observe this area as you move the choke lever.  No movement means that one or both of the problems I mentioned above is present.  If so, the fix is easy.  Just remove the tank and reconnect or adjsut as needed.  Check it out and get back to us.  Cheers.

[Rick G]

Lucky is right about gummed up passages  that  are a bear to get clean. I ahve a set of XS400 carbs that have been  dipped 4 times and still won't work right . (XS400s are famous for this)

[VK]

Yep, my bike is an 82.  I had checked to make sure external connections were correct as noted by QBS (that is, the choke cable does indeed move its attachment - whatever its name is - back and forth as intended).  I will check the overflow tubes and perhaps try giving the carbs a cleaning myself, expecting that this may or may not help.  Thanks for all of your words of wisdom!  VK

[Lucky]

if this problem just started, you have a decent chance cleaning them will help

[jasonm.]

Those large hoses are not overflow tubes... they are breather tubes. To prevent a vacumm lock situation. Sounds nuts but it's true.

[JaBey]

One thing I noticed no one mentioned is the rubber grommet inside the ends of the priming plunders. The factory service manual inparticular states that if the rubber goes bad in the plungers that it will run rich full time, thereby making the choke ineffective I would think. I just rebuilt a set last week by the numbers, and that is the first thing that comes to mind. Hope it helps.

[Lucky]

As far as I know, those plungers are not rebuildable, but jason once told me he did his..no clue how

[Lucky]

I have an old plunger here on the desk that the rubber is deteriorated, so I just took a pick and pulled out what was left. a suitable size o-ring (vinton?) should work fine to replace it, and no worry about it comming out, the cavity where the rubber sits has a little lip on it to keep the o-ring in place....  looks like Jason was right!

hmm, another little thing to do to my carbs over the winter...