Help! Evo CV Carb Jet Recommendations?

Discussion in 'Engine, Fuel and Exhaust' started by T-Skully, Mar 6, 2009.

  1. T-Skully

    T-Skully Member

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    Can anyone recommend jet sizes (low & high speed) for my stock CV carb. I have ‘96 Road King that has a K&N filter upgrade, Andrews EV27 cam, Vance & Hines slip ons and a SE 8,000 limit ignition module. I’m wanting to upgrade the stock carb but not sure which jet sizes to use.
     
  2. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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  3. glider

    glider Veteran Member

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  4. T-Skully

    T-Skully Member

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    This saying Twin Cam will it apply to my Evo also? Will the 46 be the best choice and should I try the 185 or the stock 190? I should have also mention it appears to have had power tube installed by the previous owner. Does this change the jetting options?
     
    Last edited: Mar 7, 2009
  5. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Jetting is a bit trial and error on the CV. I think with your Stage 1 upgrades, you can try the 46 low speed, and the 190 high. You might want to put a couple of washers under the needle. If the power tube you are talking about above is the YOST, that should just help atomize the fuel better. Here's a quick test that will tell you if you have too fat of a jet in the top end....

    Run the bike through the gears into third gear and run third up to 60-70 MPH full throttle, then chop the throttle about 1/8 to 1/4 back and see if the bike either surges ahead or stumbles then recovers.

    If it surges ahead, your jetting is lean
    If it stumbles and recovers , your jetting is rich
    If it makes no difference, you're pretty close.

    Quick and easy, pretty accurate too.

    This is from the first link I sent you. See earlier in that link how to evaluate the low speed jet.

    TQ
     
  6. glider

    glider Veteran Member

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    Pretty much the same when jetting for the TC or evo, maybe just stick to the 45 in the evo being it is a bit smaller. The mixing of parts from kits will sometimes give you some problems too.
     
  7. FishHunter

    FishHunter Active Member

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    The 46 may work, but if there is any sneeze at anytime in the lower rpms or when cold, then I would suggest a 48, especially on a engine with stock compression, as the carb signal will not be as strong, as one with enhanced compression.
     
  8. lzmj3s

    lzmj3s Member

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    Find a shop in your area with a Dyno. Takes away all the guesswork. Good dyno operator can give you a readout at all RPMs and save you a lot of time experimenting.
     
  9. FishHunter

    FishHunter Active Member

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    That'll ace it for sure.
     
  10. Caper

    Caper Active Member

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    Most of you time you're on the needle from 1/4- 3/4 throttle. Here's a baseline for you to start with....45 Pilot N65C needle (27094-88) a 180 or 185 main and the mixture screw turned out 2 1/2 turns out from gently seated. get the idle circuit dialed in first then work your way up to the main, you're only fully on the main from 3/4 to WOT.