Throttle Body R1150 and Rockster - Swappable?

[Soliton]

I decided to buy a second hand (right hand side) throttle body (TB) from Motorworks in the UK and get Cata in Romania to rebuild it. My aim was to then swap them out and not have the bike off the road. Although the website said the TB was for an R1150 or a Rockster they have different numbers on the body (orig 75/45-110 and re-build 75/49-116 it's also black).

My problem is that I cannot get the new body to balance and still have a normal idle speed. It runs fast 1500+

I am trying to suss out the problem but I'm not really sure where to start. It could be:

• They will never balance because they can't be mixed and matched in this fashion.
  The rebuild was not done accurately and this is having an effect on the balance.
  I am clueless and not doing it the right way.

If I can mix and match in this fashion at least one possible cause is off the list.

Things I have noticed:

• Adjusting the cable on the left hand side moves the manometer immediately but adjusting the right hand side (re-built) seems to have little effect.
  The big brass screw on the rebuilt side is nearly completely screwed down but this isn't slowing down the idle. If I then adjust the left hand side the balance goes crazy.

The original TB wasn't that rattly but it seemed like it was on the way out. After all this messing about I am tempted to put it back on but I would be a bit annoyed as I now have $200 worth of rebuilt part sitting about. I do have a 90,000 km service coming up should I just leave it to the mechanic. (He will just shake his head.)

Any suggestion (polite ones, I already feel like a big enough muppet.)

Regards,

Sol

[riceburner]

Have you cleaned out the LHS body as well?

you may have gunk on the important parts (eg the BBBA) which is messing things about.

Can anyone confirm if the body diameters are the same for the R-R and Rockster?

[acejones]

Have you tried going online to Max BMW or A&S BMW to try to determine if the parts are the same or different. You can view the parts microfiches on those sites. That may help.

[acejones]

Have you tried going online to Max BMW or A&S BMW to try to determine if the parts are the same or different. You can view the parts microfiches on those sites. That may help.

[Soliton]

Yay, just checked the fiche,

The part numbers for the black versions are the same, The Rockster had black only and the standard R1150r had black or silver. I can't reasonably believe that the colour has any bearing.

That's one possibility out of the way.

I haven't even spoken with him but I can already see my mechanic shaking his head. He is very conservative, he was almost certain that Lennie's Rocket Sprockets would either signal the end of the world or make my bike "grumpy"

Sol

[Soliton]

Yay, just checked the fiche,

The part numbers for the black versions are the same, The Rockster had black only and the standard R1150r had black or silver. I can't reasonably believe that the colour has any bearing.

That's one possibility out of the way.

I haven't even spoken with him but I can already see my mechanic shaking his head. He is very conservative, he was almost certain that Lennie's Rocket Sprockets would either signal the end of the world or make my bike "grumpy"

Sol

[Soliton]

Yay, just checked the fiche,

The part numbers for the black versions are the same, The Rockster had black only and the standard R1150r had black or silver. I can't reasonably believe that the colour has any bearing.

That's one possibility out of the way.

I haven't even spoken with him but I can already see my mechanic shaking his head. He is very conservative, he was almost certain that Lennie's Rocket Sprockets would either signal the end of the world or make my bike "grumpy"

Sol

[CycleRob]

Your inability to balance the TBs is because the rebuilt TB does not have it's blue painted idle stop screw properly set to match the closed throttle airflow of the left TB and/or the left TB has it's throttle butterfly held open too much when it's on the idle stop screw. You need to perform a shade-tree mechanic's reset so both throttle butterflys are open the same required amount when they are on the idle stop screw, and there are 2 ways to do it.

Method 1 (IF left TB idle stop screw is set OK)--Set the right BBAS the same number of turns out as the left side BBAS (usually 1.5 or 2.0 turns out), then adjust the right TB blue painted idle stop screw until your differential water manometer shows equality. That reverse engineering technique will get it near perfect IF both BBAS metering screw end cones and their passageways are clean. Do not use anything else like a TwinMax, as they are not accurate enough for this (or any Boxer motor TB synch for that matter ).

Method 2--Start all over by performing the "zero equals zero" TPS reset procedure, which should also include performing #2 above. It may be just what's needed to set things right. You'll find the overly verbose zero=zero TPS reset procedure in a .PDF file here: http://www.ibmwr.org/r-tech/oilheads/R1 ... -25-02.pdf starting at page 63.

FYI:
BBAS=BigBrassAirScrew (Idle speed adjuster)
TB=ThrottleBody

[Soliton]

Thanks Rob,

I am wondering now if I shouldn't have just saved up the cash and bought a new one from the US. This is proving to be a major pain in the butt.

Oh well, live and learn.

Sol

[wncbmw]

viewtopic.php?f=2&t=22810&hilit=throttle+body+rebuild

The link is to a thread of my own throttle body issues. The summary is there is a guy in Asheville, NC that now does the rebuilds for much less than new
throttle bodies. He told me the other week that Bing now offers the bushings, which they did not when I was having my troubles.

http://teammotorrad.com/

At the end of the thread is a link to a guy in Romainia that does the same service.

[Soliton]

Thanks everyone for your help.

I have decided to be a big sooky la-la and get my mechanic to fix it. I stuffed about for a bit and my lack of skill and the use of an azurated - dihydrogen monoxide manometer (blue water) has proven somewhat limiting upon my degree of success.

Damn I hate being a doofus. The bike is running like a snake bitten, three legged dog and I can't stand it any longer. (We have a range of very venomous reptiles in Australia.) It's embarrassing at the lights when it coughs, barks and stalls rather than idles. (I am going to get him to tighten up the rocker end play and do a 90,000km service while he's at it.)

Gave it a go.

Thanks again,

Regards,

Sol