Throttle body rebuilds

[wncbmw]

As much time as I have spent on this board over the years, one subject that either did not come up much or failed to grab my attention was that possible wear on throttle bodies making the bike run poorly. Such a problem was discovered on my '02 Roadster two days before I was to leave for the Beakster Bash this year and effectively grounded my trip.

To summarize the issues: The shaft of the throttle body that holds the butterfly valve can wear. If replaced in time, no wear to the bushing embedded in the throttle body will occur. If the steel bushing is worn too much, there is no fix I can find other that replacing the whole thing.

BMW wants $525 for the left side TB with the TPS sensor, somewhat less for the right side.

If you rely on the official BMW parts list, the TB is listed as one unit. No parts available. However, Bing makes them for BMW and has rebuild kits, with shaft and gaskets for $89 bucks. Bing also has the entire TB, complete for $413.

I would recommend everyone think about a TB rebuild at about 40K. Cheap insurance and no big deal if taken care of as a maintenance item. Can be a problem though, as I found out.

As for my bike, unfortunately, I will be getting a new left TB and will know Monday if I can just rebuild the right side.

Just a friendly heads up!

[Dr. Strangelove]

geez, Vann.

what parts are bum? A picture?

How poorly is poorly and over what time frame?
Stella! has 73k, runs great, but I am always looking for something to worry over, plus I am getting ready to leave for "out west" for a couple of weeks.

John

[Boxer]

When I traded the Black Dominatrix for my current bike, the one thing they said was wrong with it was worn TB butterfly valve shafts, making it run a little odd. I too was oblivious to that possible scenario. I did more highway miles in my 80,000 making them wear probably less over time than someone who is using them a lot in the twisties...such as yourself.

[towerworker]

I think the wear can be attributed to excessive heat buildup in the cylinder head which can be traced back to poor cylinder cooling. Vann if you had changed your antifreeze/coolant as you all know I have been preaching for years................you would now be riding in the rain merrily on your way to the Bash!

[Dr. Strangelove]

I haven't taken my beta blocker yet this morning, so of course I went down to Stella! and looked at the TB assemblies. They "look" ok, but that mustn't be worth squat? I next turned the throttle very slightly to see if I could feel any change in resistance or any tapping feel or anything that would suggest that something, like a butterfly valve, was not seating properly.

Nothing. Feels as crisp as the day I took possession of her.

I looked in Clymer's and they only reference TBSynch.

Is there a way to diagnose the problem without taking it out?

[Dr. Strangelove]

did some research and here's what I found
three refs
http://www.advrider.com/forums/showthre ... 552&page=3
http://www.advrider.com/forums/showthre ... 804&page=3
http://www.bmwmoa.org/forum/showthread.php?t=48004

[wncbmw]

Sorry for not getting back to my own thread for a while. Dr. Strangelove - I think noise (tapping) is the first clue. I apparently missed it due to ear plugs or something!

My only other clue was a little weird surging at neutral or cruising throttle. I noticed nothing when running half or wide open. Seemed to run fine.

Not sure it is anything to worry about until you feel the surge or noise. However, as cheap as the rebuild kits are compared to a new TB, it couldn't hurt. But if Stella is purring along at the moment with no sign of trouble, I would not waste any time sweating it. You will have some warning if you know what to look for, which was the point of posting this.

I am guessing it is not that common a problem but knowing the symptoms and that a cheaper fix is possible is hopefully helpful, since the answer from a dealer will only be an expensive part!

[towerworker]

Vann--how many miles on your bike? And you have to replace one TB? Can't rebuild?

[Arbreacames]

Vann, the Bing shaft replacement has been discussed on this board at least once before : http://r1150r.org/board/viewtopic.php?t=12001

From what I understand, the main problem that you have is that your bushings are worn out and that these bushings are not sold with the Bing kit. The two bushings that you need are identical except for their length. Here are the part numbers that may be matched by a bearing supplier:

812 DUM 0A (0812DU) bushing 12 mm-long, 10 mm external diameter, 8 mm internal diameter (second choice: GGB 0812DP4)
S/C 14 bushing 9 mm-long, 10 mm external diameter, 8 mm internal diameter (this one could be made by shortening the bushing above)

Pictures of the repair here: http://www.advrider.com/forums/showthread.php?t=248583

[wncbmw]

Thanks for the information Carlos. I have studied the links and will see if they help me. I am afraid, however, that some of the work may be beyond me and paying someone else to do it might cost more that a new throttle body but we shall see. I had a rider/friend who has a machine shop offer to make bushings but was laughing when he told me how much it would cost!

I will take the parts numbers to my guy tomorrow when I deliver the right throttle body and see what he thinks.

Wayne - my bike has 60k. Or would have turned over 60K on the way up to the Bash Thursday if I had made it!

[towerworker]

Starting to think about alternate riding practices that may forestall or prevent this from happening. Reckon no more grabbing handfuls of throttle when pulling off lights, slow and very light acceleration (if any at all), no more blasting around the old folks leisurely out for a Sunday drive. I guess we should start riding like old guys........................................Damn!.....some of us are!

[wncbmw]

Towerworker - if I adopted those practices, what would be the point in riding?

I don't think riding style has much to do with it anyway.

[wncbmw]

A final update on the throttle bodies. After a hunting around for a while for someone to take care of the bushing issue (and finding only folks that did not want to tackle it), I found the right guy just down the street in an old friend that I was trying not to bother with the problem.

Now, with new bushings all around (both sides), the rebuild kits installed from Bing and a fresh TB sync, it runs great!

If anyone needs this done in the future, try this guy:

http://www.teammotorrad.com/

It is certainly easier if you do it before the bushings wear out but now you know it can be done, even if they are shot!

[sweatmark]

Thanks for the follow-up on this topic!
Bing rebuild parts and preventive maintenance will have to be part of long-term Rockster ownership plan.

[rdsmith3]

I just noticed this today

http://www.advrider.com/forums/showthread.php?t=630335

I can re-haul intakes for all 1100 an 1150 BMW boxer motorcycles.

After using the bike for a few years, the spindle and the intake bushings get worn, resulting in the spindle play, resulting in that annoing rattle and may leading to bike surging.

I can fix your intake if you send it over or I cand send you a complete rebuild kit and do the work yourself.

A kit contains:

a new splindle(shaft);
necessary bushings;
set of complete o-rings;

Having the intake full repaired is just like having a new one, but at a fraction of a cost.

He's in Romania

[wncbmw]

Hey Bob - interesting link. But for the guys stateside, shipping costs to Asheville are probably less!

Looks like the same principle. I simple took mine off and dropped them off in a small box. Shipping costs would be minimal.

And I agree sweatmark - a rebuild should be part of the maintenance routine, even though BMW doesn't offer the parts. That was one reason to post my problems, to keep those oilheads on the road!

I did a good ride Sunday. It ran well!