2004 R1150RT TB synch and TPS voltage

[sundance71]

Hi Folks,

I am doing my first TB synch on my 04 R1150RT today and I was having some difficulty getting the sides balanced. I've done this on other bikes but this is my first time on the RT. Before I get too far in the weeds about what is going on, here is the current state of the bike.


12000 Miles
Good compression both sides
New plugs
Valves adjusted
New air filter
New fuel filter, internal tank lines, screen, cleaned vent holes, etc.
Balanced R1200 injectors from Tills
Throttle bodies removed and thoroughly cleaned. I did not move the idle stop screws or the TPS sensor from the positions that they were in when I got the bike.
New BBS's
AFXIED from BeemerBoneyard installed and set to 7
Aftermarket Delkevic slip on pipe. (looks and sounds awesome)
Motronic and TPS reset this morning


The bike starts right up and idles ok, but when I go to do the sync, I cannot get better agreement between the two sides than about 20-25 mm HG at idle as shown in the pic.
The BBS's are only turned out maybe .5-.75 turns to get around an 1100RPM idle. I think that most folks were reporting about 2-2.5 turns.
The TPS voltage with the butterflies on the stops (I checked) was about 425 mV from the white/red wire to the negative on the battery.

The factory paint on the throttle stop screws looks to be intact as best as I can see.
I'm not sure about the TPS sensor. There is paint on one side but most of it is missing from the other screw. (see pics)

Anyway, my question is; Based on what I've described, does it sound as though the TPS and or the throttle stop screws were adjusted by the previous owner?


I've read through Roger's procedure for resetting this and I'm good doing it. I just wanted to get a second opinion before I start tinkering with things.



Thanks
Chris

 

[sundance71]

Here are some pics of the paint on the stop screws. First pic is left side, second is right side

 

[m_stock10506]

425 mv is too high. I would get it set somewhere in the range of 365-385. You should also perform the TPS relearn procedure before you try again.

You made a lot of changes. Personally, I would have settled a baseline tune up, and then introduced one change at a time.

 

[dieselyoda]

Not to dismiss the work you have already done but practically, how much time do spend at idle?

I would look less at idle characteristics than those at 4000-4500 RPM.

That's where I spend most of my time riding and little things like throttle cable stretch, maybe an air leak or secondary ignition issue seem to show.

 

[pauls1150]

Mike's right about the TPS initial voltage; use a Quality DVM with three decimal places to see this. Also make sure that you have GOOD DVM test leads and you are making a SOLID contact to the red & white wire and the Ground point on the throttle body (brown wire). But... the computer WILL adapt to small errors; it just offsets the overall mapping a bit. (Some speculate that this takes up more addresses inside the computer... so what?)

The overall cables' adjustments can be a bit fiddley; some back-and-forth is often necessary. While the engine's "sweet spot" is in the 4000-5000 rpm range, one cannot ignore the idle settings too; if the idle is out of balance, the bike will shake side to side.

The "relearn procedure" he mentions is also important. With the key On but the engine Not running, slowly twist the throttle three times from fully closed to fully open, then turn the key Off again. This sets up an "Initial" correlation in the computer for grip position versus TPS/butterfly position.

That blue paint, while set up at the factory using their vacuum measurement tools (allegedly), is NOT "holy".
If the throttle stop screws or the TPS rotation needs to change, it needs to change. It probably won't be by much, tho.

As I've said before... the factory spec for the COLD valve clearances is a little bit too tight; some here will vehemently disagree with me on this. Set them a little bit on the loose side of spec; not only will the adjustment last longer, but you'll pull better vacuum and thereby see your change of adjustment more readily.

Also note that if you have a flaky ignition coil or an air leak anywhere (hopefully the charcoal canister has already fallen off somewhere), you'll Never get a proper balance.

 

[sundance71]

Thanks for the replies.



The bike is in really good shape so I'm not thinking that its ignition or anything. Like I said, I went all through the fuel system and it should be good there. I can double check for vacuum leaks, but I replaced the o rings when I cleaned the throttle bodies. It seems like it idles pretty well, and I was surprised when I couldn't get agreement on the sync tool.


I did do the TPS reset before starting this and my meter is a Fluke.


My understanding is that the TPS voltage should be 380mV with the screw on the stops and 250mV fully closed and the screw not making contact.

Let's say that the TPS is the only thing that got moved. Could this alone cause the imbalance? I'm not seeing how it would.

Thanks

Chris

 

[pauls1150]

Other places to check for air leaks would be the intake manifolds themselves, and the skinny O-rings that seal inside the couplings on both sides of the throttle bodies.

Make sure both throttle cables are fully seated in the little "cups" at their bottom ends. The right side somehow seems more prone to getting debris lodged in there. Verify that the "fast idle" cable has slack and isn't pulling the left side open a little.

Another potential air leak is the butterfly shaft itself, on the pulley side; sometimes you can hear a teeny rattle there. Repair kits are available for that (I forget from whom).

How about the hoses themselves on whatever device you're using to see the balance?
If you're using a TwinMax or similar, make sure it has a good battery, and a lot of people don't understand how to set the initial "Zero" on that gauge - with the hoses Not attached to the bike, set the Sensitivity to near Maximum, and adjust the zero, observing that it is stable and not drifting. Reduce the sensitivity a bunch before connecting the hoses to the bike so you don't slam the needle to one side, then gradually increase it again to just see the "flutter" between the cylinders as the sensitivity is increased; more doesn't really help.
If your gauge needs an external 12 volts, sometimes better results are obtained by using a separate battery instead of plugging it into the bike's handy accessory outlet (or other 12 volt source on the bike).

Moving the TPS "shouldn't" affect the balance unless it's waaay off; I don't see that happening.

A long shot and a WAG - is there a Lot of oil in the bottom/left/rear of the airbox? Maybe that is upsetting the fuel mix on the left side. There's a drain cap under the box, above that hot muffler.... Wedge a paper cup or a rag under it before removing that plug (1/8 or 1/4 turn CCW, just like the oil fill cap). If there's more than a tablespoon or so, somebody over-filled the crankcase at some point.

On earlier bikes, there was a service notice - check that the right-side spark plug wires are not routed too close to the O2 sensor wires; the fast pulsing of the spark plug wires may be inductively picked up by the O2 sensor wires and confuse the computer.
Also verify that the high-voltage wires from the dual coil under/behind the neck of the frame are not being pinched too tightly by those "clawed" spring clips and getting their insulation damaged.