Loss of power at high rpm

I have a 2005 R6. The bike runs fine until 12k rpm. I just had it on a dyno and everything is normal until 12k where it looks like the power drops around 25%. There is some smoke coming from the exhaust at full throttle. Also, the temperature gauge shows low temps - in the 160's.

Any ideas where to start looking?

 

Fuel pump. If you can, look at the dyno data and see if it went really lean.

 

Black smoke or white smoke from the exhaust?

 

The mixture was good and the power dropped abruptly at 12k. I don't think it's the fuel pump. The smoke was darker in color I believe.

 

What is the compression on each cylinder? any coolant in the oil or vice versa?

 

^^^ Reason i asked about the above info... would it be possible that a set of rings has gone bad and the pressure in the crankcase at high RPM is pushing oil into a cylinder? Would explain the dark smoke and loss of power. Couldnt imagine it being a coil/electrical issue if it runs fine up until 12k. However, I am a motor newbie so Im probably wrong :P

 

I need to check the compression. It's just strange that the power drops so suddenly. The dyno chart drops off a cliff at 12k. On the dyno it will keep spinning to redline, but on the bike at over 100mph the wind drag is enough that there isn't enough power to accelerate in 4th 5th or 6th.

 

I have the same bike and had the exact same problem - see this thread. My issue was that I lost a coil, yours might be the same?

http://forums.13x.com/showthread.php?t=298065

 

Worn out motor.

 

If it was carbed I say the ram air has a pinched or not connected tube.

Did you install a air filter that needs to be oiled(maybe over oiled).

Take a spray bottle and spray the headers shortly after it starts if one does not turn the water strait to steam when the other do that is where you should start. Maybe a fouled plug.

 

I'm not too familiar with the R6, but does it have upper injectors?

 

no uppers in 05 and prior.. that being said, any restriction in any of the 4 injectors will have the respective cylinder(s) running very LEAN. Real lean = heat, and loss of power. With 8 of em, you don't see this problem as obviously. You will have a loss of power with an injector flowing say 5% less, than the other 7, but it won't always run lean enough to make the engine run hot.
oh..btw, we fix that

 

He mentioned the temps being somewhat low

 

Look at the AFR curve again. If it's dropping off abruptly there likely will be a abrupt change in the AFR curve.

 

That depends, the 600RR uses the upper injectors at high RPM's, so one injector would still have a significant impact. Anyhow, this bikes does not have uppers, so it doesn't matter.

In regards to temperature, if power drops, so will the heat transfer into the cooling system, therefore the water temperatures would be cooler.

Like it was mentioned above, I would look into cylinder compression, spark plugs fuel pump, pinched lines, air intake clogged, etc...

AFR would be best if your bike has a data logger and you can take it for a test run. At speeds more air makes it to the cylinder.

 

Here's the dyno chart.

 

Do you have a PC III? If so, I would disconnect it to remove that from the equation and see if the problem persists.

 

yes, in the OP's situation he stated low temps, i was just saying that with lean conditions temps go up. Rich runs cooler. There are points of both where you loose hp and that is what running a bike on a dyno is for, to check A/F ratios AND to see what is making power. Slightly lean usually makes MORE power, but your dancing on the edge if you run too lean at tracks where your wide open for extendend periods and lean (daytona for example). You also won't see temps rise with 1 of 8 injectors being a bit lean, espeically on a track that your on and off the gas alot vs. a track that your wide open for a long time.

And I think you misunderstood what i meant about having 8 injectors being of LESS impact when ONE is slightly clogged. Having only 4 injectors TOTAL, if one is slightly lean, your lean period on that cylinder. Say 5% clogged, THAT cylinder IS 5% leaner than the rest.. With uppers only firing at mid/high rpm (same with MOST bikes with 8 injectors, nothing new or unique to one bike), the lowers fire continuously throughout the rpm range. Thus if ONE of 8 is clogged 5%, your less than 5% lean on that cylinder. That is what i was getting at, but it still is a bad thing.

i would be checking header temps to see if one or more cyl is not firing, it would show much cooler header temp. The flip the coils around to see if it follows the coil.

 

Looks exactly like mine did as well with the coil issue...

 

Its either compression, fuel, or ignition (as with most engine problems). Since you are seeing smoke (possibly oil burning), your first bet is definitely to check the compression. If the compression comes up low, its time to toss that motor in the garbage and install a new one.