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
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?
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?
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.
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.
Only at the throttle body end, but today I did adjust the grip end (LH) to find a bit more choke operation, so it's a whole lot better. Still a bit of slack in the first part of the choke.
Can't help but think there's an issue with the lever toggle mechanism here...I've not looked inside at how it operates exactly..Maybe someone could post a pic...
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:
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?
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.
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...
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
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:
Whoa careful Joe, you may end up turning into the next Lee! :stickpoke
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