1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Help! Please! 07 CBR600RR Running lean

Discussion in 'Tech' started by Focker, Jul 21, 2017.

  1. Focker

    Focker Well-Known Member

    Bike was new to me at start of season.

    As preventative maintenance, I changed the plugs and cleaned the air filter. Plugs were stock NGK from Honda.

    First time I rode it, bike would bog and be flat from as low as 7K but explode at 11000 RPM. Bike was popping and shooting flame on downshift.

    I had all 8 injectors cleaned and balanced and the next track day the performance was worse as to meet sound, I had to reinstall stock can on my full system. Did some electrical checking and found I had a short in the TPS portion of the harness, so I replaced the harness with one from a low mileage bike.

    Bike doesn't want to idle and even in neutral, if I rev it it misfires and pops at 6 or 7000 rpm. I hooked the laptop up to the bike and AFR at idle is between 15.5 - 16.5 on the Bazzaz.

    Previous owner had no problems with the bike.

    Harness is unmodified except for kill switch mod to make keyless, sidestand wire soldered together and same for bank angle sensor.

    Electronics are an HRC ECU, Bazzaz ZFI with the ZAFM module and quick shift.

    I have no MIL on the dash. Problems are consistent with both a stock and the HRC ECU as well as with and without the Bazzaz connected.

    No apparent air leaks for the lower injector seals.

    Fuel pump flows double the minimum per Honda spec and I used a fuel pressure tester to find that the pump primes to 50PSI.

    All valves are in spec.

    Map is same as it was for previous owner. I've tried a cleared map and a map from Bazzaz.

    Motor has unknown engine work other than carillo rods, ported head and web cams. NPS built the motor.

    Am I missing something? I'm taking it to the dyno guy this weekend, but I don't know if its a mapping issue or not?
     
  2. Timing sounds off to me but I would start with the basics comp and leak down test.
     
  3. Focker

    Focker Well-Known Member

    I was wondering that. The valves were adjusted before I bought it. Wonder if the cams are off a tooth?
     
  4. RM Racing

    RM Racing Tool user

    Idle means zero. Dyno is necessary..
     
  5. Focker

    Focker Well-Known Member

    Well, checked the cam timing and yup, looks like the intake cam was one tooth retarded.
     
  6. Focker

    Focker Well-Known Member

    Im guessing thats what was causing the popping on decel as well.
     
  7. Cam timing 1 tooth off is huge, you're just lucky that the 600rr motor isn't like an R6 or a 675 where 1 tooth and the valve contacts piston. Glad you figured it out!
     
  8. Focker

    Focker Well-Known Member

    Took it to dyno guy. Wasnt out by a tooth. It was out a bit though. His thought was from cam chain stretch.

    Current theories include:

    Pulse sensor, intake air control valve and finally checking compression.

    TPS is in spec.

    This thing is a real head scratcher.

    I just bought a new complete airbox with sensors injectors and throttle bodies from ebay. I wanted to get stock velocity stacks as these ones were shortened for more top end where torque and midrange punch is the name of the game at my home track.
     

Share This Page