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2010 R1200RT fueling problem / flat spot

N

Nick900

Guest
I everyone,

I bought a damaged 2010 RT that had been dropped on its right side. The face of the cylinder head had been scuffed during the fall so it was replaced with a used unit. The bike has covered 7K and the engineer who fitted the new head felt it had covered less than 7K miles due to the condition of the valves. I checked with the dealer and they confirmed the head was correct [part numbers also matched] and the valves were the same for RT's GS's etc.

I never rode the bike prior to the repair once the new head was fitted and again before riding I fitted a Remus end can and performance air filter.

Now the bike struggles to pick the revs up from 3-4K and from 5- up to the redline? This is my third RT although first twin cam. I am familiar with basic servicing and have balanced the throttle bodies several times, each time there being a good balance at 3K but everytime I test ride flat spots at the rev ranges above.

Idle is fine. A check on the plugs shows its not overfueling, if anything it appears quite lean [however I did clean the plugs thoroughly and they were quite clean to start with]. I have checked all coils and have a good spark.

Any ideas or is it 150 round trip to the dealer?

Regards

Nick
 
What happens if you got back to the stock exhaust and air filter? Basically with those changes I'd expect it to run lean so I'd start with the last changes made before I start thinking it is something major.
 
I own a 2012 RT and had some what sounds like the same issues and did a little research. I found that it appears that the manufactures tend to set up the engines to run lean to satisfy EPA and mileage issues. This causes non linear throtle responce which sounds like your problem.
Look into this product. It works for me.
Just a suggeston, I am not affiliated, just a happy user.

http://www.boosterplug.com/shop/frontpage.html

Bob
 
There's a difference between the "BMW has to meet the EPA right on the edge leanness" OE fuel tables, and running a *lot* more lean with the pipe and air filter.

The BMW hex/camhead fuel injection systems do not have intake air mass flow sensors. In order to eliminate the need for the cost of, and finding a physical place on the bike for, a MAS, the fuel tables have base values which are based on the stock intake flow, with corrections for atmospheric pressure and temperature, but not mass flow rate. The system does not have means to compensate for unexpectedly high air flow (the adaptation capability to adapt the base tables to drive the mixture to desired O2 sensor response does not appear to have enough "range" to correct for more than minor variations from nominal).

My $0.02: This sort of mid-range weakness is a classic result of installing a freer-flowing pipe more suitable for high end HP, thereby altering the back pressure in the headpipes in the mid-range in an unfavorable way. I expect that in order to address such a significant leanness in the mid-upper rpm range, you'll need to invest in a more sophisticated piggy-back electronics unit (PowerCommander, LC-1, wideband O2 sensor, etc. as Roger04RT has done (there's a *massive* amount of info in his threads on altering AF ratio)) in order to more directly control/richen the AF mixture in the flat spot ranges.
 
I guess that could be the problem. What's strange is that I also have a late 2007 model and put a full remus exhaust decat not just back box and the same performance air filter and it adapted just fine?

Regards

Nick
 
I'd consider the possibility of a weak or damaged coil. If the bike was "dropped" hard enough to damage the head (not just valve cover) the coil(s) may well be cracked. Try swapping in one or two known good coils.


Larry
 
I have tested all the plugs and coils both at idle and at about 3K revs. All seem fine. Spoke with the dealer who suggested putting stock air filter back in which I did this threw the throttle sync out. Rebalanced and did a TPS still have the same problem?

Dealer stated end can would have no effect and its also referenced on the BMW parts CD which just states fit the pipe and ride no further adjustment needed.

Still puzzled.

Nick
 
Nick
How did you test those stick coils?
You can't really test those and the only way to prove them is, swap each one with a known good one until you either find the faulty one or you are able to eliminate them as a cause.
And aren't the bottoms ones a left and right version???
 
And aren't the bottoms ones a left and right version???

yes, L & R

copied from parts fiche( not my spellin'!)

12 13 7 715 855 ANGLED IGNITION COIL, LEFT - 1 KOHM 0.35 1 $146.97
12 13 7 715 856 ANGELD IGNITION COIL, RIGHT - 1 KOHM
 
One of the "rules" taught to all beginning mechanics when I took my first course was that if you thinks its the fuel system, there's a real good chance you'll be wrong. Many, perhaps most, suspected "fueling" problems turn out to be ignition as any experienced mechanic can testify.

AFAIK there is no way to test those coils short of parts swaps- which I suggest you do starting with swapping in a known good primary on the side that took the hit. Remember that the connections to those things don't like getting yanked about so it might be as simple as a marginal connection at one.
Symptoms are very consistent with ignition.
Also, check codes just to see if they hold any clues.

If you know how to interpret and have access to a GS-911, logging real time engine data can tell a whole lot if you haven't found it before then.
 
Thanks for the suggestions. The way I thought I could test [did so] the coils was removing each one individually fitting a spare plug, starting then revving the engin to see if the plugs still sparked. I am informed this is not a reliable way of testing.

I have bought a GS911 and it should be with me by the end of the week. I am hoping the instructions are quite straight forward and it will be easy enough to either deduce the problem or post the findings.

Regards

Nick
 
The GS-911 is a handy tool but remember that even if you have an ignition problem there may be no obviously recorded code and you may still have to swap coils to check them.
Also, unless you really understand sensor controlled EFI, should you need to
resort to real time monitoring, you'll likely need some help with the interpretation...

But you won't regret having a GS-911 if you plan to do your own service work- though most dealers will do a reset of the service indicator for a moderate charge- typically about 1/2 hr shop time- for folks who do their own oil changes, etc. If you load the GS-911 on a netbook or similar, you can also load the factory RepROM disc on same and have access to tech data on the bike on the road.
 
Bought a GS911 but still no joy and bike showing no faults. Since running diagnostics the RT has been at the dealers for 3 days now and the costs are mounting. They still have no idea what is causing the problem. Nothing shows up on their diagnostic. They have tried;

All coils
Checking timing and value clearances
Throttle pot
Fuel pump
Fuel tank for water
Fuel lines

They are now saying its a case of just swapping things at random with not much hope they will get the right thing! The only positive being that its not an intermitent fault. Tech states after every change the minute he's driven 50 yards he can tell still nothing above 3K. The only thing he seems to state is it feels more like a fueling problem.

I did notice that the loan bike they gave me with my riding style gave 48mpg while mine will only achieve 36 so it would seem the fuel is not igniting in the chamber?

Dealer is running out of options and I think wants to return the bike charging me about ?Ăş600 having supplied no new parts and no closer to uncovering the fault.

Nick
 
Specifically verify the cam timing on the damaged/repaired side. Are the valves opening and closing correctly at he right time or not? This is independent of ignition timing.
 
Thanks for the suggestion. The dealer has advised the cam timing was out slightly but is now in spec and that made no difference.

Thanks

Nick
 
Thanks for the idea. I checked the exhaust prior to taking it to the dealer and tried riding with O2 sensors removed, no difference.

Regards

Nick
 
Very simple test:)

My GSA1200 devloped a flat spot about the same rpm's a year ago on a road trip. A very noticable one at highway speeds and using full throttle accel, it would go flat a second and then pick up. Mine was a simple gasoline stop, adding TECHRON to clean the injectors,etc. and the bike within just a few miles(20 maybe) was a new machine:). Actually the improvement was so dramatic, it surprised me. Has not returned, the flat spot(s). Randy:usa:thumb:dance
 
Flat might not be the best way to describe. At 3K under full load it coughs and splutters, almost like its going to stall its actually quite violent. The only way to stop it is go back to 10-20% throttle and it smooths until over 4K but its a similar story from 4 upto the limiter albeit less violent as the speed smooths out the coughing.
 
Sounds to me like someone is confused by the difference between cam timing and ignition timing with no proof cam timing has been ruled out or in..
What exactly did he change or inspect to get cam timing correct if it was in fact off?

There is no such thing as mysterious machine behavior in the hands of competent mechanics and diagnosticians- a thing few are good at in this day where parts swapping substitutes for understanding and the limits of the factory-provided diagnostic tool are all the so called techs can manage...

You are unlikely to get an answer with the shotgun approach and lack of detail in your responses in this thread and will need to record more specifics if you hope to get to an accurate answer here. If you are unable to deal at that level of detail yourself, your best bet is to hunt up the most technically respected BMW mechanic within a few hundred miles of you and take the bike to him- your current dealership obviously lacks needed skill or is restricted by instructions/limitations you've placed on them.
 
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