2007 VFR800 power drops off after 9K RPM

Discussion in '6th Generation 2002-2013' started by cwattsr77, May 24, 2022.

  1. cwattsr77

    cwattsr77 New Member

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    Hi all,

    I have a 2007 VFR800. I have had for about 9 months and not really had chance to ride it much. What riding I did was mostly local with no WOT moments. Over the past few weeks I had more time to take her out and open her up. Every time I get to around 9000 rpm the power falls off. It does not matter what gear. The feeling is almost similar to hesitation from lack of fuel or maybe spark plug breaking down. It will go over 9000 rpm but hesitates in doing so. The bike has 7700 miles and the last owner tried to remove the baffles out of the stock exhaust and failed. He replaced with a Delkavic which does look and sound nice. Is there a possibility the bike needs a PCV as the stock fuel mapping may be a problem with this exhaust. I plan to replace the fuel filter and fuel pump.
    Looking for some suggestions.

    Thanks
     
  2. squirrelman

    squirrelman Member

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    look for FI codes
     
  3. cwattsr77

    cwattsr77 New Member

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    Can you please expand. I do not have the FI light on. How do I find codes?
     
  4. squirrelman

    squirrelman Member

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    it's in the manual, read it.
     
  5. Terry Smith

    Terry Smith Member

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    Maybe the airbox is full of critter bedding or food.
     
  6. Grum

    Grum New Member

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    Even though its only done 7,700 miles, if it was mine, I wouldn't hesitate in fitting a new set of plugs - NGK IMR9B-9H's. With the fault you have, plugs need to be eliminated.
    - Never had any issues with the Delkevic exhaust on my 2009 6gen.
    - If your Fi Light is NOT on, then you have NO Active Faults as seen by the ECM. If your Fi light was on you need to have the Ignition On and Sidestand down before it will flash the trouble code.
     
    Last edited: May 25, 2022
  7. skimad4x4

    skimad4x4 "Official" VFRWorld Greeter

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  8. cwattsr77

    cwattsr77 New Member

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    Airbox is clean. I will look into changing the plugs as recommended. I watched the FI Video and will check out the bike on the weekend and see what I come up with. Thank you 'Grum' and 'Skimad4x4' for the constructive diagnostic advice. Will follow up.
     
  9. VFRJohnL6

    VFRJohnL6 New Member

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    i' ve got the same issue on my 03 bike as well.
    it gets to around 9.5k in third onwards and struggles to get past the 10k mark,it takes a while but it will get past past.
    i've fitted new plugs, new FPR, cleaned the injectors, tried a different tank & fuel pump,replaced all the vacuum pipes on the throttle bodies, balanced them as well.there are no FI lights or faults on the dash.
    it's a mystery to me.
    i've ordered another crankshaft sensor as it mabye that.
     
  10. Grum

    Grum New Member

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    Wonder if its struggling for air? Have you tried a new air filter, you don't mention anything regards the state of the air filter?

    Would seem unlikely, though not impossible I guess that a crank sensor might play up at higher RPM's, it is purely the RPM sensor, normally incredibly reliable, and if it was playing up I would imagine the bike would really let you know and the Tacho would badly fluctuate as well. Also, if the ECM detected a faulty crank sensor it would throw up a Code 19 and shutdown the engine!
    Even if it was intermittent you'd have sudden complete power loss, then a burst of power if it rapidly came good again, something you would absolutely notice.

    Might also be worth running the TPS voltage checks from idle to WOT.

    Good Luck, hope you eventually find an answer, and Please post your findings.
     
    Last edited: Jun 7, 2022
    VFRJohnL6 likes this.
  11. VFRJohnL6

    VFRJohnL6 New Member

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    cheers for the heads up Grum. i did think if i had sensor issues then the FI light would be on or coming up when the issues arose.it's got a brand new K&N filter in the air box.
    i've took off the PAIRS system, removed the O2 sensors and had the correct blanking plugs fitted, but this flat spot problem was there before i did all that.
    i've removed one coil stick at a time with a newer one and also done the same with a spark plugs, no difference.
    the crankshaft sensor arrived today and it isn't that, it's the ignition coil pick up up sensor, am pretty sure it's not that as i would be getting FI light showing.

    i'm looking to get it on a rolling road dyno tester and see if that will show up what the problem is.

    i go to the french alps at the end of this month, so it can stay as it is, at the end of the day, i'm doing 120mph in 4'th gear at 10K, so can live with it for now as i will have full luggage and a pillion on , so won;'t be going to mad out there ;-)
     
  12. squirrelman

    squirrelman Member

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    ^^^^ hook up with skimad, he'll get you sorted ! :cool:
     
  13. cwattsr77

    cwattsr77 New Member

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    So I changed the fuel pump, fuel filter and cleaned the air filter and checked the plugs and no change. No FI codes. Waiting on delivery of spark plugs but I highly doubt that's the problem. Not sure if VFRJohnL6 has any updates. Please share if you do. I have just received a new PCV today and will install soon and see if that changes anything. Also looking for a PCV map besides the Dynojet defaults. Was looking for the one from HeroRR on Youtube to no avail.
     
  14. VFRJohnL6

    VFRJohnL6 New Member

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    nothing from me am afraid mate.
    just done a 1575 mile trip around scotland and bar the issue i have with it, the bike was faultless.
    two up with the panniers and small top box was getting around 38mpg and i was riding hard and fast all the time, quite a few adventure bikes despatched in quick time ;-)
     
  15. cwattsr77

    cwattsr77 New Member

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    Sounds like fun. Being an ex-pat I miss them rides...weather permitting mind you. Will update on my finding when the weather here cools down.
     
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