BBAS cleaning?

[Ebola]

I will be doing a TB sync soon and was wondering if it would be wise to start out by cleaning the BBAS (big brass air screws) and setting them to 1.5 turns out before I even get started. Right now, my right cylinder is about 1-1/4 turn out and my left is almost 2 turns out. I know there should be about a 1/4 turn between the two of them max, so I'm thinking some cleaning is in order to start on even ground.

 

Thanks,

 

Evan

[NonComp]

Yes, I from experience, I would suggest doing that first.

[Ebola]

Good enough for me.

[Ebola]

Just for Dexterity, anyone object?

[David R]

Object? HECK NO. I cleaned the whole throttle body. Mine was gunked up pretty good after 100,000 miles. Not only did the screws need it, but the passage the air went through too. From the throttle plates IN, it was spotless.

 

She runs great now.

 

David

[Jerry Duke]

What's wrong with cleaning them and using whatever balancing method you want and then balance them? One might need to be turned in or out a different number of turns. I think using any number of turns in or out exactly the same for both could be wrong.

[Ebola]

David, you're making more work for me. I have 126k miles on my bike. I have to at least take a look now.

[David R]

I took the screws out and ran my finger nail around the ends. I got a LOT of stuff, so I went deeper. It runs MUCH better now so it was worth it. Set the TPS, balanced the throttle bodies and most important the cables. You will appreciate the work when done.

 

The screws need to be where ever the TBs are synced and idle speed is right.

 

David

[Ebola]

Clearly good advice. I checked the condition of the BBAS tonight and they had a black goo all over them. Same for the port that they live in. I will be getting in there and cleaning house.

 

I can't put a dirty bike back together.

[Ebola]

Does anyone have a write up on adjusting the TPS? Since "TPS" is not a searchable term on this site, some hints or tips would be greatly appreciated.

 

E

[LPR1100RT]

This site has lots of info in it and lots more.

http://advwisdom.hogranch.com/Wisdom/

 

[NonComp]

Does anyone have a write up on adjusting the TPS? Since "TPS" is not a searchable term on this site, some hints or tips would be greatly appreciated.

This is a good manual to have:

 

http://www.ibmwr.org/r-tech/oilheads/R11Manual/Oilhead_Maintenance_2-25-02.pdf

[Ebola]

Thanks guys, much obliged.

 

E

[flars]

My suggestion is that you stay away from the TPS unless there is some serious driveability you are trying to fix.

1 and 1 half turns out is the recommended starting point.

[Ebola]

The bike did have a stalling issue, but I found a disconnected vacuum line to the right TB and have not had a chance to ride it since then. I think I should at least check the TPS since this is a new to me bike?

 

Thoughts?

 

Also, will I do any harm if when cleaning the TB I take them off? I'd rather not have all the gunk from the TB drip into the intake of my engine.

[NonComp]

When I cleaned mine, I just removed the vaccuum lines from the nipples on the bottom of the TBs. That allowed stuff to drip out. Removing them altogether is a bigger job, because all your cables will need to be set up again.

 

My TPS voltage was way out of spec and I've never touched mine before. The previous owner probably fiddled with the factory settings. But I can see how the setting can just drift off over time. Mine was definitely worth doing and made a big difference in how the bike runs.

[David R]

IF you don't touch the throttle plate screws that are factory sealed, The TPS should be set at about .375 volts. I set it and check it with the bike running and warm because it changes with the alternator charging.

 

Here is a good write up for setting TBs

 

http://advwisdom.hogranch.com/Wisdom/TBS4Dv1.0.pdf

 

And here is the procedure for TPS

 

http://advwisdom.hogranch.com/Wisdom/tps3.1.pdf

 

Read and have fun. I did.

 

David

[Ebola]

David, thanks for the links!

 

Glen, did you remove the intake manifolds between the air box and the intake of the throttle body or did you just clean out the air inlet port that the BBAS screws into?

 

 

[NonComp]

I left the TBs connected. Just sprayed carb cleaner down the BBS port. I found that I had to fish out the passage at the bottom. I used quite a few cotton tipped swabs before it was clean. I fished a soft copper wire down he port at the bottom.

[David R]

It depends on how adventurous you are. I am a mechanic and tinkerer. I am not scared to take things apart. If you are confident, take the throttle bodies off and clean em good. If not, spray with carb cleaner and use Q tips. I had to unhook the fuel injectors to get the throttle bodies off. Do as you wish.

 

To take the throttle bodies off, I slid the air ducts back into the air box. My O rings were in good shape and the ducts went right back on. Lucky I guess.

 

Setting the cables is as import as the idle. When everything is matched the bike will run and respond like it should. I would adjust the right cable if you can and leave the left one alone. After each cable adjustment lock the nut and twist the throttle to full a couple (engine off) of times before checking again. I set mine at 1500 because its most important to me there. The farther you go up, the less important it is to me.

 

If both TBs are set as close as you can get them at Idle and the cables are matched the bike will run best.

 

Watch the temp gauge. Stop and let it cool if it gets over 5 bars. I had to stop a few times. It cools down fast.

 

Once you are close an hour (1/12 of a turn) is a lot on the BBS.

 

I got a little carried away as usual and spent about 10 hours messing with things. Checking timing, adjusted valves, adjusted rocker shaft clearances (It NEEDED it) and some other stuff while I had the sides off the bike. A valve adjust and TB sink should only take a fraction of that time. My bike is new to me and I had to explore... I even took the + cable off the starter to clean it and coat it with silicon (e?) grease. Checked the alt belt.........

 

The manual posted by GlenT helped me a lot.

 

Have fun

David

[Ebola]

I think I'll at least take the manifold off so I can look down there. I'm the type that will wonder if there is a big glob of goo in the throttle bodies if I don't see if for myself. Thanks for all the info guys... again.

[NonComp]

My manifolds don't retract into the airbox. They are from a GS, so they are longer. Makes the job a little more difficult.

[David R]

GlenT, you have me thinking about that.......

 

GS manifolds.

 

If I did do that modification, I would probably cut the intake tubes so the whole air box is used. This may keep it quieter.

 

David

[Boffin]

GlenT, you have me thinking about that.......

 

GS manifolds.

 

If I did do that modification, I would probably cut the intake tubes so the whole air box is used. This may keep it quieter.

 

David

 

David, the benefit of the GS is to take advantage of the longer, narrower tubes to boost mid-range torque/power at the expense of top-end power. Shortening the tubes would shift the rev-range at which they had an effect. In fact, all that you would then be doing is narrowing the intake tube which would loose top-0end power with little or no benefit in the mid-range.

 

The best single mod to make these bikes quieter is ear plugs.

 

Andy

[Ebola]

I took a peek last night at the inside of the TBs and they were of course covered with the same sticky black goo that was on the BBAS. Is this dirt/goo getting past the air filter or coming from the combustion chamber?

[NonComp]

Combustion vapors that get past the piston rings, via the crankcase vent that routes into the airbox on the other side of the filter. In general, I think I remember Twisty saying that some 'coking' of the TB throat does not have much impact on operation. But, yeah, I'd like to do mine at some point too. I think I'd wait until I'm replacing cables or putting a shaft kit into the right-hand TB.

[T__]

Ebola, that black goo is usually the first sign of coaking.. It builds up on the throttle body walls,, throttle plate,, BBS screws,, & BBS air passage ways..

 

It can come from many places but is usually from left over fuel residue that condenses on the TBI parts as they cool off after operation.. Some of it may be coming from the evap canister as that contains charcoal to hold the fuel vapors then those fuel vapors are purges into & through the TBI units at certain operational conditions.. Some might even be coming from a post operational drip or two from a fuel injector..

 

Throttle body cooking is & has been an ongoing problem in automobiles for years.. Some gasoline’s are better at not coaking than others..

 

As mentioned by Glenn it might even be some oil residue coming from the crankcase vent but that usually also shows up as reside in the TBI rubber boots & intake tubes..

 

Seeing as the TBI units ONLY meter air & not fuel (the fuel comes from the fuel injectors) unless the coaking is heavy on the throttle plates or where the throttle plates seat in the TBI bore it usually causes no harm.. Probably the worst place for coaking is in the BBS air passage ways as that can effect idle air supply otherwise a little black build-up in the TBI’s is harmless..

 

 

Twisty

 

[Great White North]

Here is a document with a number of procedures on throttle balancing and TPS adjustments (and many other topics). I am in the process of doing a throttle cable change on a 96 R1100RT, so am doing a TPS adjustment and throttle balancing act as part of this maintenance procedure (not that I had a choice !! :-)

 

http://www.ketchum.org/BMWmc/R1100.pdf

 

Hope the end result is smooth !

 

Cheers.

 

MLand

[Ebola]

yeah, it's in the air ducts too. It was so bad in the air inlets where the BBS lives that there were actual chunks of goo/coke. I'll feel better if I clean the whole thing out.

 

Thanks for the link MLand!

[NonComp]

It could be the result of long-term overfilling of the crankcase. There is a drain on (I think) the left-rear corner of the air box. Remove the plug and see what comes out.

[Ebola]

I'll do that.

[David R]

GlenT, you have me thinking about that.......

 

GS manifolds.

 

If I did do that modification, I would probably cut the intake tubes so the whole air box is used. This may keep it quieter.

 

David

 

David, the benefit of the GS is to take advantage of the longer, narrower tubes to boost mid-range torque/power at the expense of top-end power. Shortening the tubes would shift the rev-range at which they had an effect. In fact, all that you would then be doing is narrowing the intake tube which would loose top-0end power with little or no benefit in the mid-range.

 

The best single mod to make these bikes quieter is ear plugs.

 

Andy

 

I see your point about the affect of the longer tubes.

 

BUT Ear Plugs on a BMW? No way..... At 60 to 65 all I can hear is the wind. And the stereo if its on.

 

David

[effexer1]

 

 

"I see your point about the affect of the longer tubes.

 

BUT Ear Plugs on a BMW? No way..... At 60 to 65 all I can hear is the wind. And the stereo if its on.

 

David :)"

 

It's this wind noise that will make you deaf, unless you wear ear plugs. Go ahead, ask me how I know. But write it down...

[NonComp]

Ditto me. My hearing aids cost more than my beemer...

[Ebola]

I wear them, have for 3 years. They're a must have.

 

Damn! I hijacked my own thread.

[Ebola]

Pulled the airbox drain off last night and got a couple of ounces of oil to pour out. That should definitely be on the list of things to check when you buy a used bike.

[effexer1]

Oil in the airbox drain doesn't necessarily indicate a problem. If you overfill the crankcase, that is where the excess blows into.

[japachap]

Thought a nice pic would brighten the thread!-

Nice comparison pic.

 

Watch out for the o-rings, and also the large ones if you move the inlet pipes- they tend to get pinched and damaged.

 

Every service should begin with the BBAS/airways being cleaned!

[Ebola]

Oil in the airbox drain doesn't necessarily indicate a problem. If you overfill the crankcase, that is where the excess blows into.

 

It would be my guess that it would cause more severe "coking" of the intake and TBs than not having oil in there.

 

I like the pic. I went a step further and polished my BBS with aluminum polish to make them shiny. I got green residue on the rag, so that tells me they were still dirty even after a shot with cab cleaner. I also put a little oil on the O-ring to help make it air tight. They went in a little further being polished also. I started it up and let it idle for a few minutes and it seemed to work well. Then I noticed my throttle cables were a little catchy and not working smoothly, so ordered new ones. The bike sits for another week... Bummer. Gives me a chance to buff out my windshield.

[David R]

Do the throttle cables only "catch" when you are just opening the throttle from an idle?

 

David

[Ebola]

Actually, they have trouble returning to the home position. If I twist it full throttle, they snap back fully, but if I only pull it half throttle and let it snap, they catch before the butterflies close. They were really bad a few days ago and they were audible. I could hear things grinding inside the cable sleeve. I checked again today and it wasn't so bad.

 

The bike has 126k miles on it and I'm guessing these are the original cables. They have the metal caps on the end and from what I read in another one of my threads the new ones don't have the metal caps.

[japachap]

Just a thought re the BBAS'a- wouuldnt fitting a condensing filter in the crankcase breather pipe reduce the ammount of oily vapour that reaches the airbo and hence condenses on the BBAS instead? IIRC most cars have them, but never seen one on a bike. Seeing as the boxer motor is a bit like an old car design, maybe its a way to reduce the crud build-up?

[NonComp]

I think that 'normal' operation does not result in excess oil buildup in the air box. Overfilling the crankcase will result in some oil ending up in there.

 

There are many debates on this forum about the correct procedure for measuring oil levels on oilheads. Someimes, oil can get trapped in the oil coolers by the thermostat, resulting in an erroneous low or no oil visible on the sight glass.

 

An older engine with deteriorating rings might put more crankcase vapors into the air box. A compression test would show a problem in that case.

[David R]

Just clean the BBS when you sync the TBs after every valve adjustment. All motors have a little blow by. No big deal.

 

David