98 R1100RT My 'choke' lever has no effect

The 'choke' lever on my bike no longer induces a fast idle, not at the first setting or at the 'start' position. It barely lifts the throttle cam when I push it to the 'start' position, and doesn't move the cam at all in the first position. The adjuster on the left handle bar does not have any affect.

Ideas? Comments?

oldnslow said:

The 'choke' lever on my bike no longer induces a fast idle, not at the first setting or at the 'start' position. It barely lifts the throttle cam when I push it to the 'start' position, and doesn't move the cam at all in the first position. The adjuster on the left handle bar does not have any affect.

Ideas? Comments?

Click to expand...

Cable stretch.

I'd go with that.

mpmarty said:

Cable stretch.

Click to expand...

That was my first thought that the cable stretched. Might be as simple as re-adjust.

I'm sure a spreadsheet will follow.

I think I may have a similar problem, although it still produces some effect, but the cable sheath always pops out of the handlebar lever. Is it just a matter of adjusting until you run out of adjustment that decides it is time to replace the cable?

The fast idle (choke) cable actuates in the Bowden box and pulls the two lower throttle cables ever so slightly such that the adjustment of the lower throttle cables is critical to the fast idle lever which also needs to be adjusted precisely are crucial.

With the 1100RT fast idle lever (we all call it a choke but really, it's not a choke) there are three possibilities when it has no effect on idle.
One is that the cable has stretched with use and needs to be adjusted.
Two is that the the lower throttle cables have stretched and the free play at the throttle bodies is greater than 1mm.
Three is that they are BOTH out of adjustment.

Some time ago there was a thread on the TPS and I shot this video to explain how the Bowden box worked and that the fast idle lever (choke) cable actuated the lower throttle cables which rotated the throttle body cable spools ever so slightly. Click on image to view.

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But again, for this to work correctly there must be correct cable free play as follows:

At the handle bar:
Choke cable play:................. app. 1 mm (0.039 in)
Throttle cable play:............... app. 1 mm (0.039 in)

At the throttle bodies:
Throttle cable play:............. app. 2 mm (0.0787 in)

And if you change the free play at the throttle bodies you are going to need to re synch them.

I recently did a very good sync of the throttles, and I did leave a 'little' more freeplay in the throttle bodies that usual. I bet that is my problem. But, since I have them in the best sync I have ever had, I will leave them and just 'crack' the throttle a bit when I start 'er up.

Thanks.

Don't worry, be happy. It's nearly summer.

"Choke controls? we don't need no steenkin' choke controls!"

bikerfish1100 said:

"Choke controls? we don't need no steenkin' choke controls!"

Click to expand...

Ya, just pack a can of ether bolt

My choke lever has no effect

I'm 4 years late but I just experienced the same problem. I synced the throttle bodies on my 97 R1100GS and the fast idle "choke" stopped working. The motor runs better than ever but I have this new issue which I didn't discover until my next cold start. I marked the cable adjustment screw on each throttle body and then turned them out each exactly one turn, tightening the slack and hopefully keeping the synchronization. The fast idle works perfectly again and it feels like it's still in sync. Until reading this I didn't realize such minor tweaking at the throttle bodies would have such an effect on the "choke."
Thanks

Gordo57 said:

I'm 4 years late but I just experienced the same problem. I synced the throttle bodies on my 97 R1100GS and the fast idle "choke" stopped working. The motor runs better than ever but I have this new issue which I didn't discover until my next cold start. I marked the cable adjustment screw on each throttle body and then turned them out each exactly one turn, tightening the slack and hopefully keeping the synchronization. The fast idle works perfectly again and it feels like it's still in sync. Until reading this I didn't realize such minor tweaking at the throttle bodies would have such an effect on the "choke."
Thanks

Click to expand...

The wrongly named "Choke" pulls both throttle cables so slightly it's very hard to see. Normally you can adjust it at the handlebar enough to get it back to normal. Above I posted the clearances to go for. Even if it does not work a tiny twist of the throttle as you are starting does exactly the same thing. The engine temp and air temp sensors tell the ECU to richen the mixture and this is done automatically so no actual choking required on these engines.