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Adjusting Choke Lever

7K views 27 replies 8 participants last post by  kieran323 
#1 ·
Anyone managed to adjust this lever correctly?

I've adjusted the cable to take up a little bit of play I had in the throttle, but can't work out how to reset the choke lever.

Tried loosening and tightening the screw, and repositioning with/without throttle applied, but no joy.
 
#3 · (Edited)
Throttle adjust

The throttle cables operate on a pull to open and pull to close. The little "choke" lever just operates on a cam basis to slightly open the throttle. Choke is a misnomer as it is not a choke lever, it merely rotates the throttle a fraction. If the cables are out of adjustment esp the throttle opening cable, then rotating the toggle lever will merely take up some of the cable slack and not open the butterflys...which is the desired effect.:f4:

So , you will need to adjust the cables under the tank in the time honoured fashion until there is no slack. Not too much though or you'll open the throttle at tickover which isn't what you want.


These pics just show where the cable adjusters are under the tank...I was doing something minor at the time like changing the frame which necessitated taking the throttle bodies off the engine.; )
joe
 

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#5 ·
Cheers Joe,

I've already adjusted the cable to the point where the throttle doesn't quite return smoothly, then backed off so there's perfect throttle opening and no slack.

I'm at the point now where the choke lever is doing nothing. Before I farted about with it, it was at least opening the throttle in the last part of its quarter turn.

Do I need to reposition the lever somehow, or adjust the position of the cable?
 
#7 ·
Cheers Joe,

I've already adjusted the cable to the point where the throttle doesn't quite return smoothly, then backed off so there's perfect throttle opening and no slack.

I'm at the point now where the choke lever is doing nothing. Before I farted about with it, it was at least opening the throttle in the last part of its quarter turn.

Do I need to reposition the lever somehow, or adjust the position of the cable?
Adjust the other cable, not the one that tightens up the rotation, and do it with the "çhoke" lever in the closed position.
 
#6 ·
I have noticed that when replacing the 8 year old throttle tubes along with my stock grips, the hard plastic "tunnel" that the cable sits in has been worn down a bit from when new (from what I imagine to have been new as I've never seen a new throttle tube) and rendering my "choke" lever inutile.
 
#9 ·
Not much joy really.

Slackened off the lower cable (the return) completely, full thread showing. Adjusted the upper cable just shy of point where it stiffens the throttle, about half thread showing. Choke takes up cable in the final few degrees of turn to open the butterflies slightly. Guess there's wear there that can't be adjusted out.
 
#10 ·
Are you adjusting the cables at the grip end, or the throttle body end?
 
#17 ·
I looked for an image of the innards break-sown...not there. Maybe someone who has a bunch of spare parts just hanging around in a garage, or on a workbench, or shelving system could do "The Community" a favor....:smoking:
 
#13 ·
?

this isn't rocket science......
a cam connected to the lever pushes on the throttle tube

if there is too much slack or play in the "pull" cable, you won't get any fast idle (the pull cable is the one on top)

there is ~8mm of adjustment at the throttle end and ~12mm at the throttle body end
 
#14 ·
Could be something worn, but the cables do need to be adjusted together. Slack in one can make the throttle feel good but leave the "choke" out of adjustment still.

The real question I have is: do you actually use the "choke" or rather fast idle?
 
#15 ·
Kieran;
you can remove the lower cable entirely.....its there because of lawyers:naughty:
there'd be an ugly hole though:jsm:

and yes, i use it, in cooler temps, because it will die while i lock the garage door
 
#16 ·
According to the service manual, the max RPM you should see when the adjustment is correct would be 2500 rpm. It is a short-term use for initial warm-up that I rarely use, even here in the North East USA. I don't ride off if the bike needs the throttle boost to sta running.
 
#18 · (Edited)
I have one at home Chuck but not here...I know it's a cam but don't know how prone to wear it is...I guess logically the pull cable and it's groove in the throttle tube could also be suspect as they get the most mechanical wear in use..There could be a flat spot in the nylon groove through wear.

The fast tickover is useful imho prior to the engine coolant temp rising to say 85/90 C and the engine settling down .

On start up the cylinder head rapidly warms due to combustion...The crank however, is a furking heavy lump of cold metal and the faster the oil comes up to temp and the more oil there is feeding the journals the better...and then the crank gets up to it's operating clearances faster...which is good for its long life prospects.

This is a period where the pre 2010 F4 heat exchanger system has its uses as the coolant heated by the cylinder jacket gives up heat to the oil in the heat exchanger and the crank benefits..

So for bikes without a heat exchanger and in a cold climate ...even more important to use the fast tickover lever.

and definitely reduces "cold stalling" syndrome...

joe
 
#19 ·
i have all the bits here on my desk;
throttle, cables and throttle bodies

the cam isn't going to wear.....its pushing on the Nylon throttle tube, it always pushes the same amount, its a cam and the lever has a stop

but it won't pull on the throttle cam on the TBs if there is too much slack or play in the cable

you could set it by loosening the lock nut on the pull cable, rotating the lever fully and starting the bike.
now with the cable adjuster set the fast idle speed, now tighten the lock nut......done

thats how i did it:drummer:
 
#20 ·
Noel, when you did it that way, did you look into the TBs to see if the butterflys close completely when the fast idle doohickey is full off?
 
#21 ·
no, because the idle doesn't increase until the last 3mm of lever movement.....still goes to 4,000rpm

its at roughly at 2/3-3/4 of lever movement before the idle starts going up......no need to look at the TBs:stickpoke
 
#22 ·
Well, I suppose...but, since reading is fundamental, "the book says" 2500 rpm and the TBs should be shut when off...I think yo need to keep tweaking until you get it just right....:stickpoke

What's with all this seat-of-the-pants adjustment stuff? What, yo think you're mechanically knowledgeable?:smoking:
 
#24 ·
I've actually never checked it. It works. Good enough for me.:cross::smoking:
 
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