TFI questions.

Discussion in 'General Harley Davidson Topic' started by SeaRider04, Apr 29, 2008.

  1. SeaRider04

    SeaRider04 Active Member

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    For those of you who have TFI on your bikes, what's the third (red light) position is for? top end/bottom end/mid range?.

    I've try some of different setting on the third one from 1:0 to 4:0, but have not feel any different when riding. Mine is stock with Cycle Shack pipes.
     
  2. glider

    glider Veteran Member

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    The third pot is for top end fuel which depending on your setting on the 4 th pot should come in around 4K rpm's.
     
  3. SeaRider04

    SeaRider04 Active Member

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    so, the third and the fourth should set at same number/level?.
     
  4. glider

    glider Veteran Member

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    Depending on your setup but the 4 th is usually set at the 4 o'clock position for the crossover.
     
  5. SeaRider04

    SeaRider04 Active Member

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    Crossover?. Are you talking about exhaust pipe crossover?. (The Cycle Shack pipes does not have crossover)
     
  6. glider

    glider Veteran Member

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    Did you get instructions with the unit? They discuss the cross over from the low fuel to the top end fuel . That's what the cross over is and the 4th pot controls that.
     
  7. SeaRider04

    SeaRider04 Active Member

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    I just open the instruction and re-read it again, there isn't any section in the instruction that talks about the crossover, only thing I can find is in the "tunning section" which states.

    " The Red light pot is your main jet, it adds about 5 points of a main jet for every clock position, one clock position is the same as 170-175 main jet. All we can say about setting up this pot is to use the base setting that comes closest to your bike's modifications, then use the same method you used in setting up your carburated bikes. Good luck".

    Mine is fuel injected.
     
  8. glider

    glider Veteran Member

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    Tuning 1995-2007 Harley kits(except Gen3 kits)

    Green LED pot(1st): Air fuel mixture screw adjustment. With TFI installed
    and the bike fully warmed up, screwdriver in hand, locate the green LED and the
    pot right below it. Using the throttle raise the RPM to a high idle or about 2000-
    RPM. Once there, slowly turn the green pot clockwise from the 1:00 position (off)
    until you achieve the highest RPM and smoothest running sound (like a mixture
    screw on a carburetor). You should find the best setting between 2:30 and 4:00
    o’clock. If you turn the green pot clockwise and the engine does not accept any
    more fuel (RPMs drop when adding fuel) you may have one or more of these
    problems (See troubleshooting Motorcycle).

    Yellow LED pot(2nd): Acceleration fuel adjustment. Anytime the LED is on,
    this pot is adding fuel. In neutral raise the RPM slowly up through the mid range
    and see no yellow LED. However, opening the throttle quickly from idle you
    “should” see the yellow LED come on. Add one clock position at a time until the
    bike says too much (hesitation) then back off 2 clock positions, if adding makes it
    worse go opposite direction. The yellow pot adds most of its fuel below 75% of
    maximum RPM. If no yellow LED there is not enough load to turn it on. At that
    point the street or dyno will be able to show the difference.

    Red LED pot(3rd): Main jet fuel adjustment. It adds about 5 points of
    main jet fuel with every clock position. For example, one clock position is the same
    as 150 to 155 main jets. Fine tuning: Start with the suggested setting and then add
    one clock position at a time until the bike says too much (hesitation) then back off 1
    clock position, if adding makes it worse go opposite direction. The red pot adds
    most of its fuel above 70% of maximum RPM.

    RPM pot(4th):
    1: Sets RPM that the red LED pot (main jet fuel #3) turns
    on. All Harley. One clock position is roughly 1000 RPM. This pot should be set to
    about 70% of redline. (For example: Harley Softail redlines at 5600 rpm and 4000
    is roughly 70% of redline which would be 4:00 o’clock). Verify setting by raising
    the RPM in neutral, look for green and yellow LEDs to shut off and the red to turn
    on at the chosen RPM or refer to suggested settings if you have no tachometer.
    2: Shuts off idle fuel. In some cases modified engines
    can produce a richer than normal idle mixture. 1:00 o’clock through 6:00 o’clock
    sets RPM that the red LED pot (main jet fuel) turns on. When the 4th pot is turned
    to 7:00 o’clock the software is instructed not to add fuel until 1250 RPM. Also,
    when setting the 4th pot at 7:00 o’clock the software automatically defaults to 4000
    RPM (internally) to switch to the red LED pot (main jet fuel).
     
  9. SeaRider04

    SeaRider04 Active Member

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    I did another run with the set up above, filled up the tank and write down the mileage, take it for a ride then refill the tank, the different is two miles less than before and four miles less with the TFI installed, the bike run much much much better in all ranges though.

    Average 42 mpg without TFI, 40 mpg with old set up and 38 mpg with new set up.
     
  10. glider

    glider Veteran Member

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    You can back off on the #2 pot (accel pump) considerably with no big disadvantages and the MPG will go up.