psmoss Posted June 12, 2007 Share Posted June 12, 2007 I'll try to keep it brief, and post the details below. 2001 R1100 RT, ~20k miles Blip the throttle several times to check accuracy and repeatability of the voltage to be within .370 - .400 volts. When I do this, it seems like the voltage always changes; sometimes it stays below 400 and sometimes it's above. I think it has to with the slack in the throttle cable and having to close it by hand. Following this, reset the left throttle cable free play to .5mm. I'm not sure how to do this. Is all the adjustment done with the threads and locknut on top of the throttle body? 5 mm from where to where? Brass air bypass screws: Per some posts I had read on here, I took them out entirely and blasted them with some carb cleaner. Upon trying to re-install them, I broke both O-rings. From what I've read, BMW won't sell them alone. Are the replacements (Viton 5x 1.5 mm?) readily available or should I buy new brass screws to get them? Any tips for getting the O-rings back in without breaking them? Can I safely run the bike without them for the time being? Adjust the right throttle body cable for equal mercury readings at just off idle, around 1500 RPM. At this point, are you also taking the slack out of the right throttle body cable? A more complete picture: I bought a 2001 BMW R1100 RT a few weeks back. Having never owned a boxer before, I wasn't sure how much of the vibes were normal, and how much could be tuned out. At startup idle, the bike ran rough, shook, and would stay around 500 RPMs. The PO indicated 500 RPMs was normal. I had no indications of any service being done over the last 3 years, so I took matters into my own hands, assumed the worst, and: changed the oil and filter changed the transmission fluid cleaned the battery terminals and charged it on a tender changed the final drive fluid put in Autolite 3923s flushed the brake lines began the Zero = zero procedure and TBS I ran the bike briefly last night while I was trying to perform the TBS and I could already tell it was smoother than before, so that's for the good. Link to comment
Fugu Posted June 12, 2007 Share Posted June 12, 2007 When I do this, it seems like the voltage always changes; sometimes it stays below 400 and sometimes it's above. I think it has to with the slack in the throttle cable and having to close it by hand. Having to close it by hand? Why isn't your throttle returning freely? How much below, and how much above? I'm not sure how to do this. Is all the adjustment done with the threads and locknut on top of the throttle body? 5 mm from where to where? I'm not sure either but yes the adjustment is at the throttle body and I think the free play you want is that upon engaging the throttle, the cable should move 1/2 a mm before the butterfly starts to open. Note you said 5 mm in your post - it's 0.5 or 1/2. I eyeball it. The key is that the throttle is returning reliably to all the way shut I think. Upon trying to re-install them, I broke both O-rings. From what I've read, BMW won't sell them alone. Are the replacements (Viton 5x 1.5 mm?) readily available or should I buy new brass screws to get them? Just take a screw down to the auto parts place and find O-rings that fit on it. Next time, lightly lubricate the O-rings before reinstalling them. A drop of motor oil on your finger, wipe it on the O-ring so it's shiny. If you try to run the bike w/o the O-rings I'd guess you'll get air leakage and a wonky idle. Adjust the right throttle body cable for equal mercury readings at just off idle, around 1500 RPM. At this point, are you also taking the slack out of the right throttle body cable? You could be depending on which way you have to turn the adjuster. You might have to go back and forth if the cable is really out of whack. At startup idle, the bike ran rough, shook, and would stay around 500 RPMs. The PO indicated 500 RPMs was normal. 1100 +/- 50 is what the manual says. 500 is low. As for your plans - I would: A) Adjust valves B) TBS C) See how she runs D) If necessary screw with Zero=zero and TPS If you do the valves now, re-do the TBS because it will change, but replace your O-rings first. You didn't mention valve adjustment, given the low mileage on your RT, they could be off quite a bit - most movement happening during break in. I got mine at 10k, the valves were done by an unknown shop at 6k, and I just did them at 12k and they were a feeler guage tight. That is off more than the valves ever went on my 1100GS that had 45k+ miles on it when I got it - I think it was settled in already. While you are at this stuff, make sure that if the bike had a canisterectomy, the plugs for the ports on the throttle bodies are good (just replace them) and if you still have a canister, check the maze of lines involved (or pull it off). Those lines crack and leak vacuum at idle and can make it lumpy. BTW< I'm no master wrench, just trying to help - you might wait until you get more replies here. Link to comment
Yeeha! Stephen Posted June 12, 2007 Share Posted June 12, 2007 "Upon trying to re-install them, I broke both O-rings. From what I've read, BMW won't sell them alone..." Pep Boys sells a metric assortment box of o-rings that will work. Don't know what "space age" material they are made of, but they work. I use them on the L-Brass screws, and on the fuel line quick disconnects (1150 RT) so they are at least fuel resistant on the short term. PS. just went out and checked the box. Dorman brand Value Pack Metric O-Rings. Stock #799-450. The 5mm rings are 2mm wide instead of 1.5, but they work. Hope that helped... Link to comment
Ken H. Posted June 13, 2007 Share Posted June 13, 2007 Zero-zero is a procedure of last resort. Unless the TPS position has be dinked with, it is almost never needed, and is never part of a normal tune-up. When at idle both TB's must be on their idle stops, not hanging from their cables. If the left on in particular is, you will never read a consistent TPS voltage. The slack spec is for the top throttle grip cable, not the cables to the TBs. The basic concept is: Adjust the left one to the point where the left TB just doesn't come off of its idle stop. Then adjust the right one so the bike is in sync somewhere above idle. ISFA the large brass screws, as mentioned, any over the counter 0-ring that fits will do. Do not try to run without them however. The LB Screws will leak air past them like a sieve. Set them to an equal point, most people start with 1 1/2 turns out or there abouts. Now if the position of the TPS or the position of the left side idle stop screw have been moved, then you've got more work to do! Link to comment
psmoss Posted June 13, 2007 Author Share Posted June 13, 2007 Having to close it by hand? Why isn't your throttle returning freely? Because the cables are slacked for the TPS adjustment. Note you said 5 mm in your post - it's 0.5 or 1/2. I eyeball it. Yup, typo. 1100 +/- 50 is what the manual says. 500 is low. Indeed. And not much fun to take off on, because it's hard to keep the bike going. I killed it twice the other day. A) Adjust valves B) TBS C) See how she runs D) If necessary screw with Zero=zero and TPS I started doing A) tonight and should finish tomorrow. I've already done D), and I'm not sure I can get back to factory settings at this point. B) is in the cards once I get done with A). You didn't mention valve adjustment, given the low mileage on your RT, they could be off quite a bit - most movement happening during break in. I did the left side tonight, and they were tight. In the meantime, I misplaced my 3 mm Allen wrench. While you are at this stuff, make sure that if the bike had a canisterectomy, the plugs for the ports on the throttle bodies are good (just replace them) and if you still have a canister, check the maze of lines involved (or pull it off). Those lines crack and leak vacuum at idle and can make it lumpy. I will check, but it doesn't seem likely that anything would have been done in this regard. AFAICT, the bike received 600, 6k, and 12k services, and nothing else. In fact, there are no records to indicate anything was done in the last 3 years. Thanks for your suggestions! Link to comment
psmoss Posted June 13, 2007 Author Share Posted June 13, 2007 Yeeha! Stephen -> thanks for the info. I'll pick those up tomorrow. Zero-zero is a procedure of last resort. Unless the TPS position has be dinked with, it is almost never needed, and is never part of a normal tune-up. Wish I had known that yesterday. I suppose I was sucked in by the words "super tuning" and promises of optimal performance. Now if the position of the TPS or the position of the left side idle stop screw have been moved, then you've got more work to do! Both have been moved. If I follow the zero=zero procedure to the letter, will I actually mess anything up? I was doing fine last night up until the bit about adjusting the left throttle cable free play. Thanks again, all. Link to comment
T__ Posted June 13, 2007 Share Posted June 13, 2007 I'll try to keep it brief, and post the details below. 2001 R1100 RT, ~20k miles Blip the throttle several times to check accuracy and repeatability of the voltage to be within .370 - .400 volts. When I do this, it seems like the voltage always changes; sometimes it stays below 400 and sometimes it's above. I think it has to with the slack in the throttle cable and having to close it by hand. Following this, reset the left throttle cable free play to .5mm. I'm not sure how to do this. Is all the adjustment done with the threads and locknut on top of the throttle body? 5 mm from where to where? Brass air bypass screws: Per some posts I had read on here, I took them out entirely and blasted them with some carb cleaner. Upon trying to re-install them, I broke both O-rings. From what I've read, BMW won't sell them alone. Are the replacements (Viton 5x 1.5 mm?) readily available or should I buy new brass screws to get them? Any tips for getting the O-rings back in without breaking them? Can I safely run the bike without them for the time being? Adjust the right throttle body cable for equal mercury readings at just off idle, around 1500 RPM. At this point, are you also taking the slack out of the right throttle body cable? A more complete picture: I bought a 2001 BMW R1100 RT a few weeks back. Having never owned a boxer before, I wasn't sure how much of the vibes were normal, and how much could be tuned out. At startup idle, the bike ran rough, shook, and would stay around 500 RPMs. The PO indicated 500 RPMs was normal. I had no indications of any service being done over the last 3 years, so I took matters into my own hands, assumed the worst, and: changed the oil and filter changed the transmission fluid cleaned the battery terminals and charged it on a tender changed the final drive fluid put in Autolite 3923s flushed the brake lines began the Zero = zero procedure and TBS I ran the bike briefly last night while I was trying to perform the TBS and I could already tell it was smoother than before, so that's for the good. Patrick, good info above so will just add a couple of things.. _1st, you will NEVER get a decent repeatable TPS reading unless the throttle plate returns to a solid clank on the idle stop screw WITHOUT ANY HELP from you.. Just the slightest pressure on the throttle shaft can skew the TPS readings.. _Make sure you don’t have a tight or maladjusted cable holding pressure on EITHER side while making the adjustments.. _If you have been idling the engine with the TPS voltage over .400 volts (even for a short time) pull the Motronic fuse for a short time to re-set it.. Sometimes above .4 TPS volts at idle will cause the Motronic to act strange until a set number of complete ign cycles have been run (or you manually clear the Motronoic by pulling the fuse).. _Lastly, make darn sure your meter is hooked up to the TPS wires solidly with clean tight connections.. Unless your meter has a very good connection you can get variable readings.. When all is correct your meter should track the TPS voltage with a solid return to the same base TPS voltage each time.. Twisty Link to comment
psmoss Posted June 13, 2007 Author Share Posted June 13, 2007 _1st, you will NEVER get a decent repeatable TPS reading unless the throttle plate returns to a solid clank on the idle stop screw WITHOUT ANY HELP from you.. Just the slightest pressure on the throttle shaft can skew the TPS readings.. So how do you 'blip' the throttle and get it to return to its natural position with the slack in the cables? I had been turning it CW by hand. Link to comment
T__ Posted June 13, 2007 Share Posted June 13, 2007 _1st, you will NEVER get a decent repeatable TPS reading unless the throttle plate returns to a solid clank on the idle stop screw WITHOUT ANY HELP from you.. Just the slightest pressure on the throttle shaft can skew the TPS readings.. So how do you 'blip' the throttle and get it to return to its natural position with the slack in the cables? I had been turning it CW by hand. The throttle body shafts are spring loaded to return to idle so you can still blip them with slack in the cables (you only need to open them slightly & allow return to natural idle ).. Make darn sure the choke (fast idle) lever is all the way off & the fast idle cable isn’t pulling on the throttle body/cables.. Obviously you will need the cables in place & adjusted properly to set the off idle & mid range TBI balance but idle balance & TPS can be done with loose cables.. Twisty Link to comment
Ken H. Posted June 13, 2007 Share Posted June 13, 2007 So how do you 'blip' the throttle and get it to return to its natural position with the slack in the cables? I had been turning it CW by hand. We're not talking about much slack here, just enough to insure the TB is on it's idle stop screw. Link to comment
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