HELP!! I've farged up my T/B synch!

[redryder]

Well, since the battery was dead and I had to take the tank off to get it out and give it a good charging, I decided that it was time for the 36K service with an annual thrown in. I even went for broke and did the brake fluid change/bleed myself and it went swimmingly well...I really don't see what all the fuss and mystery is about. I'm not a master mechanic by any means, but I have maintained my own stuff for many years. I just followed the factory manual and a LOT of advice gleaned from this web site and all went well......except when I went to start the bike when it was cold.

 

I bought a TwinMax and armed with a ream of paper printed with articles from the archives here, I set to work synching the T/Bs. I started out checking the TPS for proper adjustment, and I didn't change anything because it was all well within parameters. So next I fired the bike up and sure enough it was running rough because I had moved the BBS and mechanical throttle stops down. But in a few minutes we were at operating temperature and within just a matter of minutes, I had the T/Bs in tune with themselves and mother nature and the RT was running as good, or better than ever.

 

UNTIL.... I went back later, after assembling the Tupperware I thought I'd go for a quick spin and try her out. That's when I discovered that the bike wouldn't start. If I hold the throttle open a bit, it will start, but won't idle. When I pull the (choke)(enrichener) (fast idle lever) (faux choke) [take your choice of descriptors] nothing happens at all. No change to idle speed whatsoever. If I hold the throttle open and let the bike get back warm, it will eventually idle.

 

The only thing I can think of is that when I discovered my dead battery, I was getting ready to ride the bike and had already pushed it out of the garage and, therefore, had already pulled the cold start lever up. I believe that I may have done the entire TPS and T/B work with the start lever up to the first notch.

 

Anyone with any ideas or thoughts on this one?? BTW; where does the start lever cable go to on the whole throttle schematic? I haven't seen where it connects to the throttle cable coming from the handlebar. My understanding of it is that the start lever is just a mechanical throttle advance that cracks open the throttle just enough to provide a faster idle speed while the bike is warming up.

 

Again, I have gained invaluable input from this forum and any and all comments (even the ones acusing me of being cranially challenged) will be welcomed.

[sdemeyer]

I wonder if one of the throttle cables got bumped or pulled out of it's adjuster while reinstalling the tupperware and fuel tank? I had a similar issue on my RT. The cable adjuster was broken and the cable was just "resting" on the plate, free to move around at will.

[No_Twilight]

Your reams of paper on how to do a T/B sync all start our with loosen the cables to from the throttle and fast idle lever (that's my chosen term) so that you know the throttle bodies are on the mechanical stops. Sometime in the processs you are instructed to readjust both. It sounds like you missed this step. Indeed, you may have had the fast idle engaged so it won't work now so you need to readjust it. While you're at it check your throttle free play but it soulds like you have adequate free play and probably not too much. My bike won't start when cold w/o the fast idle engaged.

 

Sounds like you did a great job with a minor malfunction. Nothing to worry about and you should be able to fix it in less than an hour.

 

Cheers,

Jerry

[sdemeyer]

BTW; where does the start lever cable go to on the whole throttle schematic? I haven't seen where it connects to the throttle cable coming from the handlebar.

 

On an 1100RT, it (along with the other two throttle cables) feeds into a "black" box just under the ABS control unit. The box slides out toward the right side of the bike. ( I learned this from this forum a while back )

[KMG_365]

Hmmm, now there's a poser!

 

I like the theory that you did the synch with the fast idle lever pulled, though I don't know how then you would've gotten a good idle synch and speed without turning those LBBS all the way in (to compensate for the slight opening of the TB butterflies). The following quote has me a bit concerned however:

So next I fired the bike up and sure enough it was running rough because I had moved the BBS and mechanical throttle stops down.

Do you mean that:

 

1) . . . you turned the LBBS's all the way in?

 

2) . . . you also changed the setting of the throttle stop screws?

 

For #1 above: this is not a bad thing, just pull 'em, clean 'em and put 'em back in, screw 'em all the way in (lightly), then back them both out 1.5 turns to start your idle-synch.

 

For #2 above: if you've changed the position of the throttle stop screws (the ones with the bolt and lock nut below the pulley) this is very different from slackening the cable adjusters (the ones with the barrel adjuster and locknut on the end of the cable ferrule on the top of the pulley). Since there is no 0=0 on the 1150's and I don't know how to find the original settings of the throttle stop screws, you might have to take it to the dealer to have these reset--if in fact I'm not misunderestimating what you've done here.

 

If it's just the former, I would start from scratch and do the #5 fuse dance (pull the Motronic fuse to reset the brain) and go from there. If it's the latter, I think I remember seeing somewhere here that there might be a way to re-set the stop screws in the proper location using a volt meter (kind of like the 0=0) without needing the BMW diagnostic computer thing-y, but you'd have to do a search.

 

Good luck.

[russell_bynum]

BTW; where does the start lever cable go to on the whole throttle schematic? I haven't seen where it connects to the throttle cable coming from the handlebar.

 

On an 1100RT, it (along with the other two throttle cables) feeds into a "black" box just under the ABS control unit. The box slides out toward the right side of the bike. ( I learned this from this forum a while back )

 

You are correct. All the fast idle cable does, is slightly advance the throttle. It works exactly the same as if you very slightly cracked the throttle open at the twist grip.

[1fastjunebug]

Hmmm, now there's a poser!

 

Do you mean that:

 

1) . . . you turned the LBBS's all the way in?

 

2) . . . you also changed the setting of the throttle stop screws?

 

For #1 above: this is not a bad thing, just pull 'em, clean 'em and put 'em back in, screw 'em all the way in (lightly), then back them both out 1.5 turns to start your idle-synch.

 

For #2 above: if you've changed the position of the throttle stop screws (the ones with the bolt and lock nut below the pulley) this is very different from slackening the cable adjusters (the ones with the barrel adjuster and locknut on the end of the cable ferrule on the top of the pulley). Since there is no 0=0 on the 1150's and I don't know how to find the original settings of the throttle stop screws, you might have to take it to the dealer to have these reset--if in fact I'm not misunderestimating what you've done here.

 

If it's just the former, I would start from scratch and do the #5 fuse dance (pull the Motronic fuse to reset the brain) and go from there. If it's the latter, I think I remember seeing somewhere here that there might be a way to re-set the stop screws in the proper location using a volt meter (kind of like the 0=0) without needing the BMW diagnostic computer thing-y, but you'd have to do a search.

 

Good luck.

 

Hope you didn't mess with the throttle stop screws as this is a no - no but can be overcome.

 

Try:

1. Make sure BOTH BBS's are 1.5 turns out and both are clean.

2. Make sure there is no binding in your throttle cable and that all cable ferrels are sitting squarely/flatly inside their adjusters. Try starting bike and warm up.

3. Loosen cable adjusters and using a common manometer, hopefully with the bike warm, adjust sync of TB's at idle using only the throttle stop screws - adjust idle to where you want it with the BBS's.

[Ken H.]

Jamie's got you started on track, but if you did indeed do the #2 item he listed, that is you did indeed adjust the stop screw of the cable bell crank on the left side, PM me and I will send you a very long involved procedure to dig yourself back out of the mess.

 

I'm hoping though that it is just that one of the cable ends got bumped out of it's retainer during reassembly. (Common.)

 

The fact that you mention 0-0 also makes me think you may want to do a bit more studying of the whole/process system as the 0-0 procedure is not applicable to the 1150 series, only the 1100 series.

[redryder]

Ken--

 

Actually, I did not know that the 0=0 was N/A on the 1150; however, I had blind luck because when I checked it, it was set and so I DIDN'T move the TPS!! I did, however, move the mechanical throttle stops back prior to starting the synch. I won't be home until tomorrow and Monday will be the earliest I'll be able to get back into the garage, but I'm optimistically hopefull that by resetting the idle speed with the mechanical stops will get me back into the ballpark. I did not close the BBSs down tightly (always a no no)but did close them and then backed them out 1.5 turns. With the mechanical stops goofed up, I had to back the BBSs out nearly three turns to get the thing to idle after warm. So it looks like I should reset the mechanical stops back close to where they were (thank goodness for dirty screws and shinny metal) and reset the BBSs back to the starting point of 1.5 out. But, I'll PM you and get the whole sorted procedure and you know what, I'll get it eventually, but I've learned a couple of valuable lessons from this.

 

I sincerely appreciate ALL of your comments for this post and take all comments and advise very thankfully.

[KMG_365]

I did not know that the 0=0 was N/A on the 1150; however, I had blind luck because when I checked it, it was set and so I DIDN'T move the TPS!!

One of the "improvements" BMW made with the 1150 was to re-set the TPS "voltage synch" electronically when you do the "#5 fuse dance". To clarify the preceding: pull #5 fuse (to the Motronic) and give the capacitor a few seconds to discharge completely--this resets any stored information that the Motronic is using to make assumptions about how you ride and other parameters. Put the fuse back, turn the key to the "on" position but do not start the bike, listen for the servo initialization, fuel pump spin-up and the computer to go through its self-diagnostic (rapid flashing red light goes to slow flash). Also make sure your kill switch is not flipped and your bike is in Neutral if on the sidestand. After all is set to start the bike (but before starting it), fully open and close the throttle a few times. Then start the bike. The computer now takes the present position of the TPS as "zero" (the baseline "voltage" is not actually zero) and now it "knows" where WOT is and it goes from there. One of the other assumptions it "goes from" is that the right side is adjusted exactly the same as and in precise synch with the left side (where it's reading the TPS voltage to know how much fuel to inject and when). So before doing this last step before your "last and final synch" be sure you've already done a good job on the valves, plugs, air filter, cleaned the LBBS's and TB's, etc.

I did, however, move the mechanical throttle stops back prior to starting the synch.

Uh huh. That explains your problem. When the throttle stops are resting on the stop screws the butterfly inside the TB is not actually fully closed. The amount of residual opening is factory set (but can be re-set, so get with Ken on that one) and the LBBS's only fine-tune the other portion of the airflow to tweak the idle synch between the two TB's--regardless, unless something else is amiss, they should stay within 0.5-1 turns of each other to achieve a good idle synch.

 

Personally, I don't think the idle synch is as important as the low-RPM off-idle synch (as the latter is where you'll be cruising around town and have the greatest chance of running into the dreaded surge) and the cruising-RPM synch (as that's where you may be spending a lot of slab time and it'll cut down on excess vibration). As long as you get the dang thing to idle fairly smooth cold at a decent RPM and not stall out at stop lights until you get it warmed up you're fine.

 

Also I should mention: make sure the freeplay in your fast idle cable (below the L/H grip) is zero. That'll help it do its job when it's cold outside. I see a lot of home wrenches who skip this part (and the throttle cable slack as well, which should be 1mm). As new cables stretch and bed-in to their sheaths, so much slop will develop in both cables that eventually the fast idle lever will do almost nothing and the slop in the throttle cable makes it very frustrating in twisty riding where you want a finer degree of throttle control.

 

We await your success stories!

[redryder]

UPDATE

 

 

With much thanks to Ken H., I've recovered the left TB to its factory position. All the cables are loose and I am ready to do the TB synch...only problem is that now the fargin! somonumbotchin' bike won't start...won't fire a lick! I suspect one of two things has happened. First, I was afraid the bike wouldn't have enough fuel with all the cables loose, so I assisted with a little throttle (normally, I don't do this, but with the fast idle cable slackened I thought it might need my help). So I may have flooded it. Secondly, I did the fuel filter change the other day, just prior to the fatal TB synch, and I didn't have a lot of fuel in it, so it could possibly be out of fuel. The kid's gone now to get me a couple of fresh gallons. I'll try refueling and see how it goes. Cranked the bike enough to run the battery dead, so now that's on the charger. Perhaps tomorrow will bring me better luck.

 

Sincere thanks for all the valuable input. I'll keep you posted. Stay tuned, there just may be a low cost RT on the market if things don't turn around...a low cost RT and a box of tools to boot.

[Pilgrim]

UPDATE

 

. . . First, I was afraid the bike wouldn't have enough fuel with all the cables loose, so I assisted with a little throttle . .

 

You're not going to flood a fuel-injected engine by twisting the throttle. The fuel pump doesn't start working until the engine rotates with the ignition on.

 

Secondly, I did the fuel filter change the other day . . .

We hope you're just out of gas. But one must look at the possibility something is misarranged on the fuel pump/filter unit. Like maybe it's backwards.

 

Good luck.

 

Pilgrim

[Kenny Haynes]

Greg, I did a similar thing on my 1100 and got bailed out by folks here. Never done an 1150, but I'm close if I can be of assistance with anything. The 0-0 got me going again after I had messed with the stop screws.

[redryder]

 

HOORAY!!! With invaluable assistance from Ken, I reset everything and got the 1150 running better than ever. Even though it was only 38 this evening, I took the RT out for a quick shakedown ride. The old beast is running smooth and strong. It started right up after I carefully followed Ken's directions and while it did take some time for me to synch out all of my many blunders, the payoff was well worth it.

 

I guess the moral of the story is that one, of reasonable skill and ability, can indeed do his/her own service work, but it doesn't pay to go into it unprepared. I had done a good bit of research, but I failed to recognize considerable differences between the 1100 and the 1150. Most of the articles I had printed out dealt with the 1100 and so I skipped blindly down the primrose path and straight into mechanical purdition. What I have learned from this is: it's ok to do things for yourself, but ASK questions FIRST. Don't get impatient and try to do it on the spur of the moment, but get help from the plethora of good and knowledgible folks here on this site. A little extra time on this site will save you hours in the garage wondering if you'll ever unfarg the things you did wrong.

 

Again, thanks to all those who provided input, I sincerely appreciate each and every one of you. But a special, extra thank you to Ken H. for your time and patience during those PMs when I thought I'd be better off putting the bike in the dumpster and selling the tools. I've learned a lot over the past week, but the thing I'm most proud of is all of you on this site...you are simply the best!!

 

Sincere thanks and gratitude

 

Greg McKinney

[Ken H.]

thank you to Ken H.

My pleasure. Great to hear that you got it back on track. Now go ride the thing!

 

Cheers!

[Softtail]

Your first problem is that you didn't need to remove the tank to remove or charge the battery. All you had to do was remove the left fairing, take off the little rubber strap, slide the battery out and unhook it. Then, maybe you wouldn't have thought about the dreaded T/B synch, and you wouldn't have farged things up. But, you would have missed out on all the fun of removing both fairings, the tank and the farging part. <<<<<Softtail>>>>>

[redryder]

Thanks softail! I hadn't heard that bit of information. Next time I'll do that and look at all the fargin I can save myself. Really, thanks for the tip.