Tube between Throttle Bodies R1100s

[phlam]

My recent purchase, a 1999 R1100s came with a few obvious mods. remus exhaust, Y connection, K&N air filter. So far I'm pleased with the lot, but I am stumped with this one. There is a hose connecting the two throttle body synch ports. On the right side of the hose just before it disappears below the battery box with the fuel hoses, there is a T connection and the port not connected to hose is capped. I assume the assembly is some sort of secondary synch device/balancing act. Is anyone familiar with this hose. Is it a mod or factory.

[brentw1]

it is for the charcoal canister
vapor recovery system

[JimMoore]

Sounds like it's leftover form the vapor recovery system. Lots of guys remove the canister and associated plumbing. Some folks leave a port-to-port tube in place to try to balance the sides. I'm not sure it works, but if the bike runs OK I'd just leave them.

[phlam]

I've only taken her out for a test ride just prior to the purchase. It ran rough (noticeable vibration) above 4000 RPMs. I decided not to take her out again until I completed the 25000 service. It was during the service that I discovered the TB connection hose. I've ordered caps for the throttle body ports as the hose ends are well worn. I've also ordered some new valve adjustment hardware as the previous maintenance crew exceeded the 8nm torque enough to strip the threads. Hopefully I will have those parts by the weekend and some nice wrenching weather. I have a twin max. When I get her back together, I'll balance the TBs and see if my vibe went away.
Thanks Fellas

[sgoodwin]

It's a big twin, it vibrates. You can only tame it so much. Being tuned correctly smooths it to acceptable levels. You can find vacuum caps for the throttle bodies at any auto parts store. Remember to use 2 feeler gauges when you set the valves. Beemer Boneyard sells a nice set for intake & exhaust. It's probably a good time to replace plug wires too, also at BB.

Just an fyi, mine doesn't really come alive until 5k, but screams from there on up with the Laser exhaust & chip, so you got some motor left to explore.

[Lowndes]

Phlam,

Congrats on the bike!! Superb handling. We need pics!!

There are a lot of improvements to be made to these bikes. Some performance, some maintenance type.

I bought a '99 R1100S two years ago, basically stock. It's been a long learning curve.

If you have not checked "the splines" (clutch splines, tranny input shaft), that would be top of the list. A few of these engines are cursed with the dreaded clutch spline issue. Easy to check them. Expensive to correct. Failure will leave you stranded.

I can tell you this: the single BIGGEST improvement I've made is an AF-Xied by NightRider. It adjusts the A/F ratio letting the engine run like it's supposed to. NO more cold natured stalling and slow speed stalling. Much better power. Runs cooler. Smoother, too.

Age related replacements (#2 & 3 - you can choose when/where to do it or the bike will decide):
Cam chain tensioner replacement, left cyl. BBY
OEM brake lines replaced with SS/teflon (Galfer or Spiegler)
HES wiring (GSAddict does it)
Clean TB's and BBS passages
If you have an AGM battery (Westco, Odyssey PC680, etc), you need to replace the Bosch voltage regulator with on from EME.

"Performance" type options:
Wilber shocks (not cheap but WELL worth it - Ted Porter's Beemer Shop)
Michelin PR4's
SJ air filter and Boxer Performance Induct (the engine has asthma, not constipation)
EV14 injectors (Injector rehab)
Rocket Sprokets also from Boxer Performance
LED bulbs EVERYWHERE.

Lots of info and discussion on all the above on this forum and others, many very knowledgeable people willing to share. Invaluable.

[phlam]

Hi Lowndes,
You wrote. "Clean TB's and BBS passages" Did you mean ABS passages. I can't figure out what a BBS is.

[BMWR502]

Originally Posted by phlam

Hi Lowndes,
You wrote. "Clean TB's and BBS passages" Did you mean ABS passages. I can't figure out what a BBS is.

Big Brass Screw.

Do not remove them to clean until you know how many turns from fully seated each screw is currently.

[phlam]

Coincidence... I purchased a couple BBSs last week along with the rubber intake manifolds (the existing ones have cracks). I'm planning to clean the throttle body and passages without heavy solvents. While in there I will determine if a rebuild is necessary. If so, that will be when the solvents come out.

I'll get the bodies synchronized at idle and +4000 RPMs after they are all cleaned up. I read somewhere that the rubber O ring on the big brass screw often contributes to the rough running. Hopefully a clean throttle body with new adjustment hardware and fresh manifolds will resolve my vibe issues.

I have a question on the cam chain tensioner. Is there anyway to tell if it has been replaced? Do I need to pull it apart and verify or is there an easier method.

Thanks Again.

[terrym]

The cap takes a 17mm wrench on the original tensioner, 15mm on the newer replacement.

[brentw1]

the spray throttle body cleaners work well just make certain to clean the edges of the butterflys
as well, I usually dont use goop type cleaners on these more messy than is required.