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#986484 - 05/04/17 01:01 PM Bushings to Bearings-throttle bodies-easy
RayBay Offline
Just Joined

Registered: 05/04/17
Posts: 7
$15-fast-easy-OilHead Throttle Body Repair with ball bearing assembly
I had a 2002 R1150RT with worn throttle shafts/bushings. Just added a bearing. Runs great.
I did NOT replace the shafts, or pull the cable pulley from the shaft.
No meter used.
===============
I marked the throttle position sensor location.
I removed and disassembled the throttle bodies, ( clips on end opposite the cable pulley's) pulled the rubber seal from the cable side recess, scraped the recess clean, froze the shaft ( freezer); tapped the bearing assembly onto the shaft ( carefully, with a tube I made) , reassembled shaft to housing ( don't break those plastic pieces for the spring).

I loosened the throttle stop screws, painstakingly centered the throttle plates ( butterflies) in the bore, while checking to a bright light, to eliminate air leaks ( high idle) and Locktite'd the throttle plate ( butterfly) screws.
I used a small piece of paper as a feeler gauge between the throttle stop screw and the throttle, set to drag thru gently, then tightened a further 3/4 turn. Locknut'd.
I set the pilot air screws to 1 turn, after cleaning them and the air holes ( carb cleaner and Q-tips).
Reinstalled, loosen cables. Less than 1 hr. per side, after the bike covers were off. Replaced TPS, lining up paint marks I had made.
Using a homemade manometer, attached to bottom of throttle bodies, and the tachometer in the dash, I used the brass pilot air screws ( BBS) to set and sync the idle speed to 1100rpm ( engine warm).
Then set 1mm cable play and synced the cables at 2500-3000 rpm.

cata motronic learn
turn on ignition, remove #5 fuse for 30sec, turn off ignition
replace fuse, turn on ignition, twist throttle to stop and back 3 times, turn off ignition.

Install the covers, go riding. ( today)
=====================
Manometer was made with 1/4" x 20' long clear plastic tube, taped to a stick, partially filled with transmission oil ( can suck it in - 6' is enough). Wife said it looked like bike was on life support ( intravenous).

2002 R1150RT throttle shafts were worn, at the cable side bushings; except for 3mm, where the shaft seal is in a recess in the exterior of the throttle body. An 8mm x 13mm x 3.5mm ball bearing assembly will tap onto the shaft, then fit in the recess for the seal ( remove the seal).
No other changes were required. No play at all. Throttles turning smooth and easy.
Bike runs the best since we got it. 75,000 miles on odometer.
SMR138XZZ 8mm x 13mm X 3.5mm ABEC-3 Stainless Steel Bearing available from www.rcbearings.com or E-bay.com ( US) same outfit, I think e-bays cheaper. shipping included.
Each bearing and manometer was about $5 each.

Tool: To tap the bearing onto the shaft. I made a 4" long driver tube with one flat end larger than 13mm ( to push against the bearing) with a 21/64" hole (to fit over the throttle shaft). I lubed the throttle shaft. Could alternatively drill a hole in wood, place a washer with a 21/64" hole over it, then the bearing, then gently drive the shaft through the bearing ( don't drive the shaft out of the cable pulley).
================
I believe that if the shafts are loose in the bushing ( worn), the factory throttle stop screw ( idle speed screw) setting doesn't mean much. Also, on many bikes, who knows if they've been changed.
Backing off these screws allows the throttle plates ( butterflies) to center and seal, before tightening. There's lots of room in the throttle plate screw holes for mis adjustment. I also have some throttle plates that are slightly different shapes, don't know if that's wear or manufacturing.
The paper feeler gauge technique is to set the throttle plate angles the same. Then I adjust air screws ( BBS) for the final idle sync.
Some inet sites said 0=0 doesn't work on this bike, and that this newer motronic adjusts itself ( when reset as above).
I did try other settings first, this is what worked for me.

Disclaimer: If you do this, it's your responsibility.
I don't anticipate any more wear issues, but I never talked to Murphy.

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#986487 - 05/04/17 01:13 PM Re: Bushings to Bearings-throttle bodies-easy [Re: RayBay]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 13014
Loc: Ohio
Morning RayBay

Did you use sealed bearings? If not did you do anything to prevent vacuum leaks at the bearings when the grease eventually degrades & disappears?
_________________________
D.R. ___
Sent from my rotory dial wall phone!

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#986494 - 05/04/17 02:47 PM Re: Bushings to Bearings-throttle bodies-easy [Re: dirtrider]
RayBay Offline
Just Joined

Registered: 05/04/17
Posts: 7
The bearing is stainless w/metal shields both sides.
This is the ONLY bearing that size, I could find.
Fits in recess 1 side, against cable pulley on the other, but I understand your concern.
Or maybe they'll last forever, one way to find out.
It was easy to do, and I did save a bunch of $.
I've had airhead carb shaft/bushing wear similar to these throttle bodies.
I think they could have used a better design where the bushings wear instead of the shafts, and were easily replaceable.
There does appear to be 8mm x 13mm x 4mm bearings available but probably the seal recess would have to be deepened.


Edited by RayBay (05/04/17 03:54 PM)

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#986646 - 05/06/17 03:39 AM Re: Bushings to Bearings-throttle bodies-easy [Re: RayBay]
RayBay Offline
Just Joined

Registered: 05/04/17
Posts: 7
Modified from original post
$15-fast-easy-OilHead Throttle Body Repair with ball bearing assembly
I had a 2002 R1150RT with worn throttle shafts/bushings. Just added a bearing. Runs great.
I did NOT replace the shafts, or pull the cable pulley from the shaft.
No meter used. But it cost $5/side, works perfectly so far, and the wifes riding it now.
===============
Bearing
I marked the throttle position sensor location.
I removed and disassembled the throttle bodies, ( clips on end opposite the cable pulley's) pulled the rubber seal from the recess in the cable side of the housing, scraped the recess clean, froze the shaft ( freezer); tapped the bearing assembly all-the-way onto the shaft ( carefully, with a tube I made) , reassembled shaft to housing ( don't break those plastic pieces for the spring).

Air Flow
I loosened the throttle stop screws, painstakingly centered the throttle plates ( butterflies) in the bore, while checking to a bright light, to eliminate air leaks ( high idle) and Locktite'd the throttle plate ( butterfly) screws.
I used a small piece of paper as a feeler gauge between the throttle stop screw and the throttle, set to drag thru gently, then tightened a further 3/4 turn; to set the throttle plate angles the same. Locknut'd.
I set the pilot air screws to 1 turn, after cleaning them and the air holes ( carb cleaner and Q-tips).
Install throttle bodies, loosen cables. Less than 1 hr. per side, after the bike covers were off. Replaced TPS, lining up paint marks I had made.
Using a homemade manometer, attached to bottom of throttle bodies, and the tachometer in the dash, I used the brass pilot air screws ( BBS) to set and sync the idle speed to 1100rpm ( engine warm).
Then set 1mm cable play and synced the cables at 2500-3000 rpm.

Fuel/TPS
cata motronic learn
turn on ignition, remove #5 fuse for 30sec, turn off ignition
replace fuse, turn on ignition, twist throttle to stop and back 3 times, turn off ignition.

Install the covers, go riding. ( today)
=====================
Manometer was made with 1/4" x 20' long clear plastic tube, taped to a stick, partially filled with transmission oil ( can suck it in - 6' is enough). Wife said it looked like bike was on life support ( intravenous).

2002 R1150RT throttle shafts were worn, at the cable side bushings; except for 3mm, where the shaft seal is in a recess in the exterior of the throttle body. An 8mm x 13mm x 3.5mm ball bearing assembly will tap onto the shaft, then fit in the recess for the seal ( remove the seal).
No other changes were required. No play at all. Throttles turning smooth and easy.
Bike runs the best since we got it. 89,000 miles on odometer.
SMR138XZZ 8mm x 13mm X 3.5mm ABEC-3 Stainless Steel Bearing available from www.rcbearings.com or E-bay.com ( US) same outfit, I think e-bays cheaper. shipping included.
Each bearing and the manometer were about $5 each.

Tool: To tap the bearing onto the shaft. I made a 4" long driver tube with one flat end larger than 13mm ( to push against the bearing) with a 21/64" hole (to fit over the throttle shaft). I lubed the throttle shaft. Could alternatively drill a hole in wood, place a washer with a 21/64" hole over it, then the bearing, then gently drive the shaft through the bearing ( don't drive the shaft out of the cable pulley).
================
I believe that if the shafts are loose in the bushing ( worn), the factory throttle stop screw ( idle speed screw) setting doesn't mean much. Also, on many bikes, who knows if they've been changed.
Backing off these screws allows the throttle plates ( butterflies) to center and seal, before tightening. There's lots of room in the throttle plate screw holes for mis-adjustment. I also have some throttle plates that are slightly different shapes, don't know if that's wear or manufacturing.
Some inet sites said 0=0 doesn't work on this bike, and that this newer motronic adjusts itself ( when reset as above).
This is the ONLY bearing that size, I could find. They listed 180 left.
Bearing is small stainless steel, w/metal shields both sides, inner race sits against bushing.
I believe there's close to 0 airflow through the bearing, not enough to affect idle.
There does appear to be 8mm x 13mm x 4mm bearings available but possibly the seal recess would have to be deepened. The only ones I found with seals were 4mm wide ceramic. Scared to use ceramic, because tapping them might break them??.
I did try other settings first, this is what worked for me.
I don't anticipate any more wear issues, but I never talked to Murphy.
Hopefully it lasts awhile or forever. One way to find out.
I've had airhead carb shaft/bushing wear similar to these throttle bodies.
I think they could have used a better design where the bushings wear instead of the shafts, and were easily replaceable.

Disclaimer: If you do this, it's your responsibility. No guarantees/warranties.
It wasn't my fault
I wasn't even here/there that day
I cnt Evn spl N-gnere
I'm dead anyway! Epitath: He said he would take the wifes bike apart to take pictures.
Warranties come with new bikes.
I don't know if it could ever turn out even worse than the stock bushing setup.

But it cost $5/side, was easy to do, works perfectly so far, and the wifes riding it now.

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#986651 - 05/06/17 09:40 AM Re: Bushings to Bearings-throttle bodies-easy [Re: RayBay]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 2507
Loc: Massachusetts
Your bearing replacement idea is intriguing, and it will be interesting to hear how it holds up over time. As long as they don't leak air, as DR pointed out earlier it seems they should work well but time is always a good judge.

Centering the throttle plates in the bore is also important.

The alignment procedure you've described won't reliably align and sync the throttle bodies. A mechanical alignment with a paper feeler gauge can get you started but you need to then perform a zero=250mV procedure on the left throttle body, locking the throttle stop when the TPS is at 340mV. Then the BBSs should be set to 2.5 turns and the right TB should be aligned to the left with a manometer (or differential gauge like the Harmonizer). This equalizes the throttle bodies under the load of intake manifold vacuum, properly sets the TPS voltage and opens the throttle plates the correct amount at idle. I can pretty much guarantee that your throttle plate opening at idle and TPS settings are off at the moment.

Then set idle to 1100 with BBS on a HOT engine (you have to be sure the engine is running under Closed Loop Motronic control so that the start up enrichment is gone), then cable slack taken out per BMW procedure, then the right/left balance set for 1100-2500 RPM. When you're done the throttles should come off the stops at the same time and hit WOT together. Lastly, the fast idle lever should be set to open the TBs to about 3 degrees in the mid detent position.

Here is a description of the procedure: https://forums.bmwmoa.org/showthread.php...=1#post1003851.


Edited by roger 04 rt (05/06/17 09:46 AM)

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#986674 - 05/06/17 05:44 PM Re: Bushings to Bearings-throttle bodies-easy [Re: roger 04 rt]
RayBay Offline
Just Joined

Registered: 05/04/17
Posts: 7
Hi Roger
The R1150RT is running better than it ever has since we owned it.

I read 150 to 300 posts on adjusting throttle bodies, including some of yours, many applying to older motronic units. The procedures/hype/paranoia on throttle stop screws seemed overly complex for what is basically the same as a idle speed screw on a carburetor. My lawnmower carb has more parts and does more things. ( also the airhead constant velocity carburetor). I decided to make a simpler procedure.

I deliberately decided to separate AirFlow/Balance and Fuel/TPS.
That is, to simply balance the actual airflow, before and separately from adjusting the TPS.
I realize fuel mixture ( TPS) affects idle speed, and I did try different settings. The 3/4 turn is what worked for me, and also gives a baseline to adjust up or down from ( evenly).

To spread the bearing idea was the reason for the post, the rest just works, for me at least.
It cost $5/side, was easy to do, works perfectly so far, and the wifes riding it now.

When I originally attacked this bushing /shaft repair issue, I deliberately tried to think outside the box/lines, think of a better repair. It appeared there was a lot of people trying to restore a system that was known/guaranteed to fail.
I noticed the 3mm good piece of shaft remaining on the cable end, was trying to find a 8mmx13mmx3mm nylon/teflon washer style bushing, that might wear out as well, but would give me a year or 2. Then I came up with the bearing idea.
I do think you understand the TB/TPS issues as good or better than any other posts I have read, and have saved a lot of OilHeads. If we ever have any issues, I may drag out the multimeter and turn the TPS. For now, it's perfect for me.
RayBay

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#986675 - 05/06/17 05:45 PM Re: Bushings to Bearings-throttle bodies-easy [Re: roger 04 rt]
PAS Offline
Member

Registered: 06/24/11
Posts: 630
Loc: N.E.Ohio
What is the cause of this wear? Spring pressure to high?

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#986694 - 05/07/17 02:18 AM Re: Bushings to Bearings-throttle bodies-easy [Re: RayBay]
nrp Offline
Member

Registered: 12/22/04
Posts: 746
Loc: Minnetonka MN
There will always be a small amount of dusty air ingestion that will cause wear in the throttle shaft. That dust will contaminate the roller bearings but just how badly remains to be seen. A seal in addition to the bearing would be highly desirable, but lets wait & see how this new fix performs.

Some means of measuring the L-R air-flow match vs throttle plate opening at ~20 inches of vacuum with a given amount of Big Brass Screw openings would be desirable. That may very well be the source of surging as the mixture control system relies on similar L-R characteristics to keep the Air/Fuel ratios of the two sides within a combustible range given only one throttle position feedback.

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#986702 - 05/07/17 10:16 AM Re: Bushings to Bearings-throttle bodies-easy [Re: RayBay]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 2507
Loc: Massachusetts
Originally Posted By: RayBay
Hi Roger
The R1150RT is running better than it ever has since we owned it.

I read 150 to 300 posts on adjusting throttle bodies, including some of yours, many applying to older motronic units. The procedures/hype/paranoia on throttle stop screws seemed overly complex for what is basically the same as a idle speed screw on a carburetor. My lawnmower carb has more parts and does more things. ( also the airhead constant velocity carburetor). I decided to make a simpler procedure.

I deliberately decided to separate AirFlow/Balance and Fuel/TPS.
That is, to simply balance the actual airflow, before and separately from adjusting the TPS.
I realize fuel mixture ( TPS) affects idle speed, and I did try different settings. The 3/4 turn is what worked for me, and also gives a baseline to adjust up or down from ( evenly).

To spread the bearing idea was the reason for the post, the rest just works, for me at least.
It cost $5/side, was easy to do, works perfectly so far, and the wifes riding it now.

When I originally attacked this bushing /shaft repair issue, I deliberately tried to think outside the box/lines, think of a better repair. It appeared there was a lot of people trying to restore a system that was known/guaranteed to fail.
I noticed the 3mm good piece of shaft remaining on the cable end, was trying to find a 8mmx13mmx3mm nylon/teflon washer style bushing, that might wear out as well, but would give me a year or 2. Then I came up with the bearing idea.
I do think you understand the TB/TPS issues as good or better than any other posts I have read, and have saved a lot of OilHeads. If we ever have any issues, I may drag out the multimeter and turn the TPS. For now, it's perfect for me.
RayBay


Ray, I could see that the main reason for your post was to explain how to repair the TB bearings for $5 per side and what you did seems smart and economical. Well done!

It's too bad that you read hundreds of TB alignment posts, some for R1100s because the BMW procedure is straightforward and reliable (the link in my last post). It's the one that others who try your bearing fix should follow.

Deciding to try a new alignment method for the TBs is your call but you should at least know that the process isn't the same as adjusting the idle speed screw in your lawnmower. The principal difference is that the BMW process is doing at least three things simultaneously: adjusting idle speed, balancing the L/R power for your TBs and [u][/u]aligning your TBs and TPS to your Motronic[b][/b]. You accomplished the first element and possibly the second but unlikely the third (alignment to the Motronic).

Edit: And by aligning the TBs and TPS to the Motronic, the BMW process also set cold-start idle speed and cold-start AFR enrichment--two key elements of cold-start idle quality.


Edited by roger 04 rt (05/07/17 10:34 AM)

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#986710 - 05/07/17 12:27 PM Re: Bushings to Bearings-throttle bodies-easy [Re: PAS]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 13014
Loc: Ohio
Originally Posted By: PAS
What is the cause of this wear? Spring pressure to high?


Morning PAS

The spring is not the main cause as it doesn't pull in any one direction (it is circular around the shaft)

There are many factors on the BMW TB shaft & bushing wear, from engine vibrations, to engine vacuum pulsations, to constant movement while riding, to lack of lubrication, to entry of carbon & coking from the inside, to constant vacuum pull from the engine side, to throttle cable off-center loading.

Probably the biggest loading is in the form of atmospheric pressure pushing on the outside of the throttle plate due to engine vacuum on the engine side of the throttle plate lowering atmospheric pressure on that side.

BMW/Bing made the correct choice in using a bushing for the throttle shaft due to constant vibration & only a partial shaft rotation while in use but probably could have done a better job of sealing the bushing to shaft area with "O" rings or some sort of seals & possibly made a replicable wear surface on the throttle shaft.

Just a fact of life that 2 cylinder engines (basically a 1 cylinder as far as intakes are concerned) with their harsh intake pulsations are hard on throttle body & carburetor throttle parts.
_________________________
D.R. ___
Sent from my rotory dial wall phone!

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#986717 - 05/07/17 02:47 PM Re: Bushings to Bearings-throttle bodies-easy [Re: dirtrider]
PAS Offline
Member

Registered: 06/24/11
Posts: 630
Loc: N.E.Ohio
D.R. I also wondered if the higher compression was in play to cause the wear. I have an 81 R100RT with over 170K and the shafts and bore are fine. Bike is a low compression engine.

I recently seen a post by Chris Harris and his thoughts were that the wear was due to insufficient free play on the throttle cables. In that regard, does the dealer do that adjustment on new bikes or do they come that way?

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#986724 - 05/07/17 03:19 PM Re: Bushings to Bearings-throttle bodies-easy [Re: PAS]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 13014
Loc: Ohio
Originally Posted By: PAS
D.R. I also wondered if the higher compression was in play to cause the wear. I have an 81 R100RT with over 170K and the shafts and bore are fine. Bike is a low compression engine.

I recently seen a post by Chris Harris and his thoughts were that the wear was due to insufficient free play on the throttle cables. In that regard, does the dealer do that adjustment on new bikes or do they come that way?


Afternoon PAS

Probably not a compression related problem but could be a little camshaft profile related. The throttle plates on the BMW 1100/1150 engines are quite large so have a lot of surface area.

On the tight throttle cables-- They are ALWAYS tight while riding the bike (if they weren't then you would have poor & uneven throttle control)

Could tight throttle cables effect the bushing/shaft wear? Sure if you idle the engine for many hours at a time each day with just the right cable tightness to allow the engine firing pulses to rattle the throttle plates. (is it likely?-- Probably not)
_________________________
D.R. ___
Sent from my rotory dial wall phone!

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#986734 - 05/07/17 05:55 PM Re: Bushings to Bearings-throttle bodies-easy [Re: RayBay]
RayBay Offline
Just Joined

Registered: 05/04/17
Posts: 7
Hi guys- my 2 cents, and thanks for your excellent input, I do appreciate it

To PAS -Our throttle shafts/bushings were worn mainly on the cable/spring side.
We also had '81 and '83 R100RT's in Aussieland, we put on 30k km, carbs similar to yours , dusty conditions, shafts wore like crazy.

To nrp -Ball not roller bearings with 2 Side Shields, but I agree they may eventually become contaminated. But I avoided replacing the shafts and bushings which would fail again eventually anyway.

To Roger - I may someday turn the TPS to the indicated voltage for idle, which I believe would end up really close to the same result.
( joke) - I just checked and the throttle stop screw does fit in my lawnmower :-)

To dirtrider -Re: Bushings are a "correct choice", I could agree, especially if they lasted :-), maybe a larger diameter surface area on the cable side, different materials.
( joke) it's a Beemer, it doesn't vibrate :-)

To the world ( and Dan Cata) - ! ( light bulb) If a person ( named Dan) made a stepped nylon/teflon/oilite/unobtainium bushing that also filled the 13mm recess, with an o-ring on the end, instead of the shaft, thereby giving more surface area
And/OR made a throttle shaft with a larger diameter on the cable side ( up to the cable pulley), bored the Throttle body ( cable side) to a larger diameter, inserted a nylon/teflon/oilite/unobtainium bushing that would wear instead of the shaft,
-( joke) could also add a harley chain oiler for bushing lubrication :-) . OK, that's not funny.

--OK, back to the shop, don't touch wife's bike, don't touch wife's bike, don't touch wife's bike,
Come to think of it, It's working fine. Put my hands in my pockets, walk away.

RayBay

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#986901 - 05/09/17 06:02 PM Re: Bushings to Bearings-throttle bodies-easy [Re: RayBay]
RayBay Offline
Just Joined

Registered: 05/04/17
Posts: 7
Here ( I hope) is a picture of the shielded bearing pushed partially on the shaft, the shaft placed at the seal recess beside the bushing, the old seal on a piece of paper, the drift that I made to tap on the bearing. Also shows the throttle plate screw hole size vs screw diameter.


Attachments
TB with bearing.JPG (56 downloads)



Edited by RayBay (05/09/17 06:03 PM)

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#996698 - 09/12/17 02:20 PM Re: Bushings to Bearings-throttle bodies-easy [Re: RayBay]
RayBay Offline
Just Joined

Registered: 05/04/17
Posts: 7
UPDATE- a few thousand miles later, bike hasn't missed a stroke, runs great at low RPM. No popping from exhaust.
Here ( I hope) is a picture of the bearing pushed partially on the shaft, the shaft placed at the seal recess beside the bushing, the old seal on a piece of paper, the drift that I made to tap on the bearing. Also shows the throttle plate screw hole size vs screw diameter. Also a picture of the shielded bearing.
Added Picture location, maybe.
[img]https://lh3.googleusercontent.com/J-dWz7...No=w601-h451-no[/img]
[img:left]https://lh3.googleusercontent.com/q8W7_I...1m=w138-h137-no[/img]

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