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#762129 - 02/26/12 09:52 PM Cursing at my BBS
aterry1067 Offline
Member

Registered: 10/02/10
Posts: 169
Loc: Southern Maryland
Hi all. Went to do a TB sync today, and it was a tad bit off, so I decided to adjust as usual. First step, remove the BBS's in the throttle bodies. The right side came out fine, I cleaned it, and reinserted as normal. The left side, was jammed in tight and wouldn't budge. It isn't bottomed out, as I did the sync last summer. It came out fine then, with no abnormalities.

Has this ever happened to anyone? Any thoughts or reasoning of why its locked in tight? I have all but stripped the head with a large screw driver and channel locks (it still barely moved, less than an 1/8 of a turn, and creaked when it did). Two new ones are on order. My only guess is it's coked up?

Any thoughts?

Other than that, all the maintenance went great today. Haven't had to adjust the valves in over 10K miles, and they were spot on today.

Thanks in advance for any input.
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aterry1067
2000 R1100RT

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#762133 - 02/26/12 11:44 PM Re: Cursing at my BBS [Re: aterry1067]
nrp Offline
Member

Registered: 12/22/04
Posts: 645
Loc: Minnetonka MN
Force it & when it strips out, try Beemer Boneyard for a used throttle body etc. Before reassembly of both throttle bodies, clean the ports, bodies, & BBSs thoroughly with carb cleaner.

Use a flashlite to set the throttle stops for the tinyest opening off of closed (like +1/8 turn), and the BBSs 1 1/2 turn out. Assemble & readjust those throttle stops for balanced and correct idle, then set the TPS for .385 V.

If necessary, tweek the BBSs for final idle balance.

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#762134 - 02/26/12 11:50 PM Re: Cursing at my BBS [Re: aterry1067]
garr2 Offline
Newer Member

Registered: 05/27/10
Posts: 41
Loc: Vincentia, Australia
As far as I know my BBS had never been removed and cleaned in 5 years. This is what one looked like when I cleaned them last year -



I guess if enough of this muck built up on the threads/shank of the BBS & the throttle body it could seize. Either that or the o-ring could disintegrate and foul the thread. I'm just guessing though. Would carby cleaner sprayed on the edge of the BBS head penetrate enough to soften/dissolve the muck? I'm thinking an in tact o-ring might prevent this. Let us know what you find.

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#762145 - 02/27/12 02:11 AM Re: Cursing at my BBS [Re: aterry1067]
Boffin Offline

Administrator
Member

Registered: 10/02/04
Posts: 8521
Loc: Leicestershire, UK
My RH BBS got jammed tight. Many applications of heat, followed by penetrating oil followed by a well-fitting screwdriver turned by a spanner got it out eventually. I cleaned up the TB threads with a chaser and fitted a new screw.

Andy
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Andy Long

2004 R1150RT : traded for:
2002 R850R SE
1986 K100RT
2013 Kawasaki W800

"No man ever got very high by pulling other people down. The intelligent merchant does not knock his competitors. The sensible worker does not knock those who work with him. Don't knock your friends. Don't knock your enemies. Don't knock yourself." Alfred Lord Tennyson

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#762152 - 02/27/12 05:41 AM Re: Cursing at my BBS [Re: aterry1067]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 8111
Loc: Ohio
Morning aterry1067

That happens occasionally, usually due to heavy coking or a very dry "O" ring that allows corrosion in the ring slot.

DO NOT FORCE IT!, if you do you will probably strip the screw slot out.

As Andy says heat & penetrating oil.

Personally I use a small pin point torch (you can get a cheap one at Harbor Freight for about $6.00 or so.

Use the pin point torch to lightly heat the brass screw itself, then apply penetrating oil as it is cooling. Then try to move it, if still tight do the heat & penetrating oil again-- & again, etc.

It might take a few tries but eventually the heating & cooling will suck the penetrating oil in past the "O" ring & free the BBS up.

Once out & clean make sure the "O" ring isn't damaged (if so replace it). Then put some good quality (02 sensor safe) silicone grease on the "O" ring when reinstalling. If you do then next time it will move easily.
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#762154 - 02/27/12 06:13 AM Re: Cursing at my BBS [Re: dirtrider]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 1850
Loc: Massachusetts
Good morning DR, Is there O2 safe Silicone grease? Glad you mentioned it. On another board a guy mentioned using Silicone grease on the TBs and it sounded like a problem waiting to happen since silicone is said to foul O2s.

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#762156 - 02/27/12 06:18 AM Re: Cursing at my BBS [Re: roger 04 rt]
dan cata Offline
Member

Registered: 06/13/09
Posts: 979
Loc: Romania
Originally Posted By: roger 04 rt
...since silicone is said to foul O2s.


I think "poison" instead of foul is the right word smile

Dan
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Stuff I make for BMW bikes

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#762163 - 02/27/12 06:48 AM Re: Cursing at my BBS [Re: roger 04 rt]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 8111
Loc: Ohio
Originally Posted By: roger 04 rt
Good morning DR, Is there O2 safe Silicone grease? Glad you mentioned it. On another board a guy mentioned using Silicone grease on the TBs and it sounded like a problem waiting to happen since silicone is said to foul O2s.


Morning Roger

Good point.

The silicone grease we use at work IS supposedly 02 sensor safe, it comes from Dow but the tubes are not marked with any data or technical data. This has been brought up many times in our engineering meetings & every time we bring it up we are told it is indeed 02 safe & it doesn't outgas any harmful gases.
It better be as we use it for injector "O" ring lubrication as well as other on-engine seal lubrication on one of a kind very high value test vehicles. We seldom fail 02 sensors anymore unless we are trying to during a test sequence.
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#762169 - 02/27/12 07:29 AM Re: Cursing at my BBS [Re: dirtrider]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 1850
Loc: Massachusetts
Thanks. Why not just use motor oil, or does that harm the rubber?

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#762178 - 02/27/12 07:57 AM Re: Cursing at my BBS [Re: aterry1067]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 8111
Loc: Ohio
Morning Roger

I believe some people do. Motor oil will probably swell up the "O" ring slightly (not sure that hurts anything though). And motor oil usually turns gummy after a while.

I have seen everything from refrigerant seal oil, to chassis grease, to white lithium grease, to soap, to motor oil, to 2-cycle oil, to Vaseline, to silicone grease, to ???? used on those "O" rings. They all seem to work OK on original assembly. I haven't been around when they were moved a year later so I can't say how any of them worked long term.

I do have experience with silicone grease long term & that I KNOW works slick as butter after long term heating cycles & dirt/moisture intrusion to the "O" ring area.
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