BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

R1150R 2002

Dear All:
What is the correct method to set the idling at 1150. Mine is around 1000 therfore the alt. light comes on at times.
I do not want to goof up, bec I do not know much about the Fuel injected machines.

Thanks in advance

MK

The BBS (big brass screws) on the throttle bodies are used to adjust the idle however, unless you have a manometer or Twin Max or similar device, I wouldn't mess with them.

Isn't the BBAS to enrich/weaken the mixture?

MK

The mixture is adjusted by the ECU based on readings from the TPS, Oxygen sensor, temperature, and what not (technical term). At idle, the initial mixture is based on the fuel map set by the factory (unless you have added a Power Commander or such).

The BBAS set the baseline and do indeed have an impact on the mix, they meter more air into the fuel injector, the ECU acts from there. Idle, between 1050-1100 rpm is the baseline. If the alternator light is coming on, perhaps the belt needs attention.

Here is a link to the sync procedure if you have a TwinMax. I have sync'd mine using a homemade manometer. Once I find that link I will post that for you as well.

Wayne

http://www.advrider.com/Wisdom/TBS4Dv1.0.pdf

Thanks for clearing my misunderstanding about the BBAS. I understand now that the BBAS keeps the butterflies open for idle similar to carb bikes. BBAS increases/decreases idle speed, Right?

What are the lower throttle adjustments for, I mean the lock nuts and the outer sheaths?

Thanks
MK

The BBS don't keep the butterflies open, that is an external stop screw on each throttle body that does that (don't adjust these!). The BBS are an air adjust screw, more air= faster idle. They control the air the motor runs on before the butterflies open and take over. Just like the idle air control valve on your car. Turning the BBS out -counterclockwise (absolutely evenly) will increase your idle speed, sounds like you would only need to turn counterclockwise about the width of the screw slot itself to get the idle where you need it. BUT I would defininately got the syc. checked with some sort of manometer (carb stix, twinmax etc.) asap after doing this. Hope this helps.

mkmd555

If you don't have a manometer or a TwinMax you can still adjust the BBS slightly with little cosequence. Turn each BBS the same amount, probably you will not reqire more that 1/16 of a turn. Your idle balance might be off a bit, however we are not talking about a lot of air flow into the engine at idle.

Your TB (Throttle Body) sync will not be affected as they fall under a diferent adjustment.

It is however and excellent practice to sync both the idle and the TB's as our bikes, opposed twins, don't run their best if the adjustments are off, specially the TB's.

As always, my friend (but sometimes misguided) boxermania is correct about adjusting the BBAS without a twinmax or manometer IF you make duplicate adjustments to both. The BBAS adjust the amount of air passing thru a cast in passageway that bypasses (goes around) the closed throttle plate. It's a quick/easy/precise way to adjust the balanced idle speed when the (blue painted) idle stop screw cannot, must not be adjusted from it's EFI calibrated minimum opening factory setting. If you have only 1,000 RPM idle, then 1/4 turn CounterClockwise to each BBAS will give you the speed you need until a "wrench" with a synch tool can dial it in perfect. That wrench can very inexpensively be YOU if you construct your own dyed water differential manometer. Here is a how-to starter for you:
http://www.powerchutes.com/manometer.asp

When I made my 2nd one I improved on the flimsiness and short usable range of the yardstick model by using 15 feet of tubing, tubes touching side-by-side, a 4 foot long board and no scale graduations (They're not needed). With the 2 tubes adjacent to each other for their full mounted length, it's real easy to see the slightest difference in the reading (no parallax error).
http://i142.photobucket.com/albums/r87/ ... Manom2.jpg
http://i142.photobucket.com/albums/r87/ ... Manom1.jpg

.

Since we are on this topic does it matter if my idle is not at 1150 and its oh lets say 800 or 900 ish???? maybe but definitely under 1000. I was told by my dealership guys that it didn't matter at all and not to worry about it. What do you boys think?

Wando

There is really nothing wrong with the idle at 800 - 900 rpm as long as the engine doesn't kill and the alternator is generating positive current.

On the other hand, our bikes being opposed twins they posses the side to side mtion of the big pistons and this is somewhat more noticeable at the rpms you are running, The engine at the correct idle speed will vibrate less, let's say smooth out......your call.

As far as the alternator light coming on, mine will do that too if I start it up and let it idle. However, if I blip the throttle, the light goes out and then stays out while idling around 1000 rpm. It has done this since new.