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  1. #1

    AFR - No guessing should be allowed

    We have all heard read "read your plugs" right"?
    Good luck!, as with today's gas it is about an impossibility, and most people have no idea how to do it anyway.
    Pulling in the clutch and hitting the kill switch for most every road condition is certainly boring and even dangerous (work on the side of the road)
    The EZ solution is to install a wideband AFR wideband meter.
    I use AEM but there are others /.
    The hardest part is welding in a bung -use the front exhaust as that one usually runs leaner.
    Now your guesswork is gone as the AFR will read faster than 3 inputs per second.
    I used to think I could tune a carb, well.....I now know I am a much better tuner.
    With 10.5 to 1 compression, it brings comfort me to take a glance at the AFR and absolutely confirm I am in a safe zone and not slowly driving a hole in a piston.
    I can fine tune the carb for RPM/load.
    No guesswork required.
    Next, it is better than the dyno because most dyno rooms will send you out the door TOO lean!

    It is the best tool I have added to my inventory in a long time. albeit I leave it on the bike.

  2. #2
    Iron Butt smitty901's Avatar

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    We agree that reading the plugs with today fuel and plugs leaves a wide range of error. Many headers now have the bung in them. The 2-1 Python I had on on the 1996 while the sidecar was on it has the wide band bung in it.
    Dianne Feinstein:
    "All vets are mentally ill in some way and government should prevent them from owning firearms."

  3. #3
    Well that is a good thing!
    But welding a bung in is a simple task for a welding shop even of ya do not know how.
    I thought I would post that first as we get this EVO forum involved.
    Carb people can see this thread.
    No more asking guessing about jetting needed!
    I have found my slightly moded CV carb carries a real even AFR ration to about 90MPH. After that as speed increases, it will slowly richen also.
    No one would know this with just plug checks.
    Perhaps because the main jet is fully taking over?
    I have tried the HSR 42.
    I can find no difference in performance.
    It is said they come off the line faster.. The seat of the paints scale does not notice it.
    But with my raised ports in the mail, I might have to go back to it as the CV supposedly will only support fuel up to about a 100HP.
    I am pretty sure it will do more depending on the application.
    Again-The AFR will explain it all to me.

  4. #4
    Iron Butt smitty901's Avatar

    Join Date
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    2017 RGU Blackhills gold and black-96 FB Black with sidecar
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    With older carb bikes you have a lot of wiggle room. Now if you racing it and every last dollar you have is on the line then it may be more important to narrow it down some. Gave up long ago chasing very last Hp, Torque , or RMP out of an engine. What I want is starts first time every time. Hot or cold weather. You would be surprised at how many will not reliably start below 30 degrees
    The great part about the EVO was if you did not screw it up the breast held up very well to day to day riding. So many EVO's were trashed by Bubba.
    Dianne Feinstein:
    "All vets are mentally ill in some way and government should prevent them from owning firearms."

  5. #5
    The carb I love for one huge reason-None have ever made me walk home.
    Not once not ever.
    Car or bike.
    I have had to pull a couple apart through the years on the side of the road for a sticky needle seat....
    But, no tow.
    I ride long distance and do not relish the idea of a computer being in control of my bike (or car)

    True, if I was a real racer Fuel injection is the way to go for a 100 reasons.
    However, my track is a lot longer than a 1/4 mile.

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