Left Throttle Body Throttle Stop

[saddleman]

I have a 1997 R1100RS a friend brought to me & the left throttle body does not return to the stop screw. I've never worked on any of the R bikes in the throttle cable area & can't find the reason why it won't return to the throttle stop. Any idea what I might look for ?.

Thanks, Dave

 

[m_stock10506]

Hard to tell, but the throttle stop screw doesn’t look like it has been moved which is probably a good thing.
What about the throttle cable? It should have a little bit of free play. Is anything pulling or catching the throttle cable? Can you get some slack into the throttle cable?
If you look into the throttle body, can you see the butterfly and is it closing all the way?

 

[saddleman]

The left butterfly is not closing. The right side works fine. It has almost 50,000 miles & I have read that is a good mileage to replace the the whole throttle cable system.

 

[m_stock10506]

Disconnect the throttle cable at the TB pulley and see if the butterfly closes to the throttle stop screw. If it does, then the cable is holding the throttle open. You have to find out why the cable doesn’t have any free play.

 

[skoss]

Looking at your last picture, it seems to me that the outer tube of the left bowden-cable is not properly seated in the distribution box. Therefore, the cable is under tension and slighty opening the throttle body.

Stefan

 

[saddleman]

Disconnect the throttle cable at the TB pulley and see if the butterfly closes to the throttle stop screw. If it does, then the cable is holding the throttle open. You have to find out why the cable doesn’t have any free play.

The butterfly closes just fine with the cable disconnected.

 

[saddleman]

Looking at your last picture, it seems to me that the outer tube of the left bowden-cable is not properly seated in the distribution box. Therefore, the cable is under tension and slighty opening the throttle body.

Stefan

In that picture the cable is unhooked from the throttle body. When you push the box back in you can feel the cable seat in the box.

 

[jsouth]

The butterfly closes just fine with the cable disconnected.

Seems to me that your answer is right here. As others have suggested, this is a cable problem and not a throttle body problem.

 

[pauls1150]

Dunno if the 97 RS uses the same setup, but on my 97 RT, I swapped the entire cable system (including the distribution box & fast idle line) for the "updated" version - seemed smoother to twist (maybe just 'coz it was new?), and it was easier to balance. So the answer (to me, at least) to post 3 is Yes. The old box had some crud build-up inside - maybe that's where your hang-up is?
Do not lube these cables! They have a nylon (?) inner sheath, and oil distorts that.
"New" cables stretch, so you'll have to re-balance a couple of times to keep it "right".

 

[saddleman]

Seems to me that your answer is right here. As others have suggested, this is a cable problem and not a throttle body problem.

I've known all along the throttle body was ok.

 

[saddleman]

Dunno if the 97 RS uses the same setup, but on my 97 RT, I swapped the entire cable system (including the distribution box & fast idle line) for the "updated" version - seemed smoother to twist (maybe just 'coz it was new?), and it was easier to balance. So the answer (to me, at least) to post 3 is Yes. The old box had some crud build-up inside - maybe that's where your hang-up is?
Do not lube these cables! They have a nylon (?) inner sheath, and oil distorts that.
"New" cables stretch, so you'll have to re-balance a couple of times to keep it "right".

I'm pulling the box all the way out tonight & take it apart.

 

[happy wanderer]

I've known all along the throttle body was ok.

OK. Then quit looking at it. Start at the top. Is the cable seated in the twist grip assembly properly? If yes then the issue is a bad cable but more likely there is something not seated properly in the Bowden box.

There is nothing else in that cable system. Usually this happens when the end of the cable sheath is not all the way into the adjuster at the throttle body or is hung up and not seated in the tri pulley in the Bowden box.

 

[saddleman]

The steel crimped sleeve at the end of the cable in the junction box was off the end of the outer sleeve. It took a lot of effort to get it back on the cable.

Thanks everyone, Dave

 

[bc1100s]

If yes then the issue is a bad cable but more likely there is something not seated properly in the Bowden box.

Give this man a kewpie doll !