'04 R1150R high idle issue BBS (Idle Screw) fully seated

Here are the details:

2004 r1150r
11500 mi. (not missing a digit)
afxid set at 5
r12 injectors
newly installed stick on left. went out last month
balance and throttles set using carbtune pro
Plugs are good, valves are within spec, new air filter

Hi All-

Have a strange issue I'm working on. I decided my bike was not running correct so I proved it. I had a few issues after a 1200mi trip in June. Bike began to sputter and pop. I noticed it was much hotter on the left side as well. Research and investigation proved the left stick coil was bad. Now replaced. I also replaced both injectors with the new r1200 model upgrade. Because of these changes I decided to check the balance and reset idle as the left BBS was about 1.5 turns out further on the left than the right.

I had it set proper this a.m. both at idle and around 3500rpm with idle established around 1100 (I did not hook up my 911). Carbtune showed a nice vacuum balance. This evening I went for a ride. Smooth, sharp throttle, well balanced, running strong. After it was good and warm, I noticed the idle was around 1500. When the throttle was blipped, it went down slower but steady to 1500rpm. I pulled over in the shade to turn back the BBS screws evenly, 1/4 turn each side. I kept turning and turning each side. The Idle dropped slightly and now the BBS are both completely seated tight and closed.
It still runs great!! What the heck?? It should be sputtering and chugging along in some ugly way, and certainly not acting like a hotrod, peeling out of corners, front end wanting to pick up. What is this witchcraft?
As for the throttle, there is 2-5mm (this is a guess, it's not tight) slack at handle and each side of throttle bodies. Both sides snap back to the stops. High idle switch/lever seems to be set fine, opens, closes with a noticeable difference and was needed to start up this evening.

This is a new bike to me, and my first boxer. Previously I had an '97 F650st. I like to wrench so am learning as I go. The bike runs well but mpg has always been low. Currently averaging 35 mpg over 30 fuel logs. Not good. Possibly the enrichened fuel from the afxid? Even so, that's pretty low even with a heavy right hand. Once I sort out the idle/BBS setting I can focus on mpg.

Any thought on this idle issue? Not sure where to start, but tomorrow, I will give it a good morning wake-up and come home to see if everything is balanced, think it through, do some more research.

Thanks for the help-

Eric

First thoughts are that the valves are set too tightly, and/or the TPS (throttle position sensor) is not properly set.

The factory spec for the valves is - in my opinion, and others disagree with me - too tight.
Hopefully you're aware of the little slot marks on the cam sprockets? They should be pointing straight "out" when at TDC, and verify that both rockers exhibit a little freeplay, to ensure which stroke of the cycle you're on. I set my valves DEAD COLD at about .007 to .008 intake, and .013-.014 exhaust. My bike starts easily and runs great.

TPS alignment procedures are covered in other threads in this forum; you'll need a Quality digital voltmeter that can accurately see about 380 millivolts, AND let you know if/when you've gone too far in the "low" direction and the pot's wiper has dropped off of the resistive element by "floating" at ~0.00 +/- millivolts... You need to find the "Zero" point, but not "less than" that.

Also make sure that the BBS's passageways are clear and clean, the O-rings are in good shape (not letting air flow by cracks in the rubber), and that the tips of the BBSs themselves are clean - buildup here will affect the idle balance.

Around town, I'll get ~ 35 mpg, but this increases significantly if I spend more time on the freeways.

Thanks Paul-

I will inspect the valves again. I have been using specs. Is there another mark or place I should be looking beyond the inspection hole and the "ot" mark? I always do a full rotation to be sure all valves are open on the side I am working on. Also checking the BBS and cleaning.

As for the TPS, I have only tried to "retrain" by a disconnect of the #5 (i think) fuse, waiting an hour or so. Three easy full throttle movements with key turned but not started. I believe I an go through the process using the GS911 as well will give it a shot.

Thanks-

Eric

Pauls1150 said:

First thoughts are that the valves are set too tightly, and/or the TPS (throttle position sensor) is not properly set.

The factory spec for the valves is - in my opinion, and others disagree with me - too tight.
Hopefully you're aware of the little slot marks on the cam sprockets? They should be pointing straight "out" when at TDC, and verify that both rockers exhibit a little freeplay, to ensure which stroke of the cycle you're on. I set my valves DEAD COLD at about .007 to .008 intake, and .013-.014 exhaust. My bike starts easily and runs great.
.

Click to expand...

You should make it clear that your valve measurement is INCHES, not mm. The typical (factory) spec for 1100/1150 valves is .15 and .30 mm. .007 works out to about .18 mm. .014 is about .35.

Thanks Mike-

I got a pair of gauges from the Boneyard .15 & .30
I generally have them in place to a point where they are "snug" but cannot fully stand up tight with pressure, slide out easily.

Eric

Valve adjustment will not cause you to seat the BBS screws to get the idle down.

I suspect the previous owner may have messed with the throttle stop screws.
Is the blue sealing paint still there on both sides?

Is the paint still present on one of the TPS screws?

I suspect an air leak.

PGlaves said:

I suspect an air leak.

Click to expand...

Agree with Paul. With engine warm, spray some carb cleaner around each throttle body where it slips into the rubber boot and where the boot bolts up to the head. If engine speed changes, you have a leak, which is causing your issue.

For the uninitiated, and non Oilhead owner, what is a BBS? Is that a BMW acronym? I know what a BFH is though!! I'd like to modify the title for future searches.

The Idle speed screws.
Big Brass Screw

GSAddict said:

The Idle speed screws.
Big Brass Screw

Click to expand...

Figured as much! I've changed the title for future searching...the forum doesn't search on three-letter terms.

↑↑↑↑↑ All good info; somehow I forgot about air leaks!
Please forgive my blatant heresy in using American measurements for a foreign machine.

Thank you for all the replies.

So, I did double check the valves, they are to spec.

As I was doing so, I also noticed the inner cover seal for the spark plug/coil hole was bent over on both sides. I can assume that was me. This may have been leaking. However I did ride it today and the rpm was still at 1300+-

Unfortunately on my way home, a piece of road rebar punctured my rear tire (we have some nice potholes around Joliet) this took up my afternoon. Well fortunately I signed up for the MOA Platinum Plus program and will now be getting a new free rear tire! Membership does have its benefits.

The bike was running just fine last week so I am not sure how the idle got so far off. It was set to 2.5 turns+- from seated.

Both the stop screws and the TPS paint are intact.

The bike was a clean and gently ridden 4700 miles when purchased.

So for now its: 1) fix the tire 2) check for air leaks 3) check throttle cable housing is seated and correct, nothing binding.

One thought I also had is a "Chicken and egg" question:

If the TBS can only accurately be set after a proper Idle has been established at running temperature, How does one set (lower) the Idle if the TBS screws are fully seated?

Eric

Check the throttle cables to make sure they are seated and not hung up, but also check the cable pulleys to make sure there isn’t some sand or grit wedged down in the groove.

Best,
DeVern

20774 said:

Figured as much! I've changed the title for future searching...the forum doesn't search on three-letter terms.

Click to expand...

Thanks for that.
I know this can be a common issue (idle adjustment issues) as I did a search, WAY too many pages came up. The titles were helpless.
Should there be a sticky or an FAQ page devoted to the BBS (Big Brass Screw) for ease of reference?

This may be of use... https://ibmwr.org/original/r-tech/oilheads/R11Manual/Oilhead_Maintenance_2-25-02.pdf. YMMV

Check for a small pebble wedged in one of the throttle pulleys.
That can explain a sudden change

It's all good!

So, for a belated update. New Metzler installed, working on scrubbing off the elephants on the tire edge, no need for those or "chicken strips." I have been riding with the high idle, knowing I needed to get it right. I went for some 100mi. rides over the weekend to and around Starved Rock State Park then decided to check the issue again. Problem solved.

I assumed and checked both throttle stops "visually" but not PHYSICALLY. The left throttle was off the stop by about 1/32". After I seated this and reset the low idle with the BBS, then the high idle, the Manometer reads smooth and even. All fixed and happy.

Thanks for the insight and assistance!