Odd throttle stop situation???

[redman9]

HI all...Kevin here, new to the BMW world but 35 yrs biking and wrenching so...
Just picked up a 2004 R1100S twinspark and love it. Now I am doing all the check and tune-up stuff a new owner does. Checked and adjusted the TPS. Adjusted valves. Synch'ed the TBs. Therein lies the issue. There is plenty of slack at the cable ferrule at the throttle/grip. The snych went well enough. I look closely under the throttle bodies and discover that neither side has the circular holder that the cable rides in...back against the actual stop screw at idle!!?? Bike idles at 1000, snych'ed fairly easily with homemade manometer. It appears that the idle setting is obtained by the throttle cables being adjusted and not the stop screws. This can't be right. If I remember correctly the BBSs were at 1 turn and 1 1/4 turns out. What gives? Do I (should I) have to go in and loosen all cabling, make sure butterflies close completely, set TPS at it's lowest, set idle speed with stop screws, set TPS to read 380 at THAT point, adjust cables for 1mm slack etc?????

[bill pierce]

Can you take a picture and post it?

[sgoodwin]

Idle speed is adjusted with the air screws, be sure to keep sync adjusted when doing this. It is recommended not to adjust the idle stop screws at the cable adjusters as these are set at the factory. Not sure why they don't rest on the stop screws unless cables are adjusted too tightly.

[blutruck1]

How'd you set the TPS without the blades closed?

Cables should have some slack at the TB's.

BBS screws set the idle along with the throttle blade stops, and TPS setting.

If you have even pressure at idle and 3k or there 'bouts, bike idles and runs smoothly, I'd leave it alone. Otherwise, you'll need to reset cables, TB stops, TPS, and BBS. All sorts of info here on doing TB synch along with other BMW sites. You'll need to do a search.

[redman9]

Well pix would be very difficult considering the location we're talking about...up behind the TBs. I have idle and synch and TPS at 390 but the idle stop screws are not touching the tabs of the cable actuator discs/whatevers. The circular sheet metal wheels that the cables actually wrap around and pull on. I'm thinking I need to remove the tank and tupper to check the cable junction. Am I right that the 2003/2004 twinspark has a cable junction block under there somewhere? The factory manual shows NOTHING. The earlier models had throttle going to left side and then from there to right side but later models have throttle going to junction block and then two cables from there to TBs??? I can do a zero-zero and start from the bottom so to speak...if I need to. I don't like the idea of the butterflies always hanging on cable...never resting on the stops at idle. What say thee gurus????

[EZ-RIDER]

Sounds like the adjustment nut at the main throttle cable is to tight, back it off !
No need to pull the tank!

[redman9]

I wish it was that simple....there's plenty of slack up at the throttle! That's why I'm wondering about a "cable junction box" under the tank.
Anyone have a blow-up of a manual showing this cable junction????

[LeftCoast Peter]

Yes redman, PM me your email addy. and i'll send you it.

[blutruck1]

If the TB throttle plates are "hanging on the cable", then the adjusters are not adjusted correctly. There should be slack between the cables and the rotating portion of the throttle plates contained in the throttle body, those "circular sheet metal wheels that the cables actually wrap around and pull on."

Nothing in the junction block under the tank will affect this and there is no adjustment there, as long as the cable housings are seated properly, which they probably are. Only adjustments are on the TB cable anchors where the cables screw into the TB. One on each side for each cable. Handle bar throttle adjustment should have slack, which it does according to you.

So, that means that for some reason all the slack has been removed at the TB and this has pulled the TB plates away from the stop. Are you absolutely sure there is no slack in the cables at the TB? Are you sure that the plates aren't seated against the stop? It's very hard to see this without a mirror or removing the air filter to TB air intake tubes.

I'd suggest you make sure that you have a problem here before you go and create one, because it's easy to do with TB's, BBS, TPS, manometer, and Internet.

[David R]

Just a few thoughts.

First, the throttles should touch the stops. Its the way it was made.

Next, The adjustment could be at your choke or idle up control. It has a cable adjustment on the handlebar.

If the throttles don't both hit the stops, it will be inconsistent especially after a few thousand miles.

I would back the cables off at the throttle bodies and find out how to get rid of the slack at the twist grip. Perhaps there is an adjustment there too.

For pictures, try MAX BMW parts finch on line. As far as I KNOW there is no adjustment at the junction box.

David

[redman9]

OK, mystery solved for now....thanks everyone!
The choke/fast idle cable was hanging up under the front areas somewhere. I played around with it and when I moved the clip-ons to above the triple clamp I rerouted it. All is good. I am not sure if it was like this when I did the TPS TBS etc but it runs great now so I'll leave it alone until my Techlusion comes in. I'll do another TPS check, TB synch and idle adjust after install.Cheers all!

[EZ-RIDER]

Redman9 check your e-mail

[redman9]

EZ...check yours..