Plug reading 101

Discussion in 'Technical Posts' started by imlostagain, May 18, 2002.



  1. Rich Rohrich

    Rich Rohrich BioHazard

    Joined:
    Jul 27, 1999
    Messages:
    22,269
    Media:
    6
    Featured Threads:
    5
    Likes Received:
    10,942
    Trophy Points:
    1,325
    Once you have enough time to get a good reading if the conditions stay the same the ring will tend to stay the same. The problem is most people tend to ride at something other than WOT and weather has a way of changing over time so the conditions rarely stay the same for very long.

  2. Jaybird

    Jaybird Apprentice Goon

    Joined:
    Mar 16, 2001
    Messages:
    7,099
    Likes Received:
    0
    Trophy Points:
    36
    Then one can assume that those who practice "predictive jetting", (taking into account all known variables and jetting by chart as a result of measurables) are a step ahead of the game and can, in fact, keep that lil bugger close to the same size, yes?

    :confused:
  3. Rich Rohrich

    Rich Rohrich BioHazard

    Joined:
    Jul 27, 1999
    Messages:
    22,269
    Media:
    6
    Featured Threads:
    5
    Likes Received:
    10,942
    Trophy Points:
    1,325
    I've never seen a "generic" chart that works for all situations or even particularly well in general, but over time good note taking and regular measurement of known variables will allow you to build a bike specific chart of your own. Once you have a baseline and have an understanding of how atmospheric changes impact those baseline settings you should be able to easily make changes without ever pulling a plug.

    You'll almost never see Eric Gorr pull a plug on one of his rider's bikes. That's not a coincidence. ;)
    Last edited: Jan 26, 2005
  4. whyz

    whyz Subscriber

    Joined:
    Nov 18, 2001
    Messages:
    480
    Likes Received:
    0
    Trophy Points:
    0
    Good questions Mike.
  5. Rich Rohrich

    Rich Rohrich BioHazard

    Joined:
    Jul 27, 1999
    Messages:
    22,269
    Media:
    6
    Featured Threads:
    5
    Likes Received:
    10,942
    Trophy Points:
    1,325
    That would depend a lot on what type of riding he is doing.
  6. Kaw_Boy_5

    Kaw_Boy_5 Rookie DRN Member

    Joined:
    Apr 18, 2001
    Messages:
    253
    Likes Received:
    0
    Trophy Points:
    0
    If this is the correct way to read for the main jet what is the correct way for the other circuits? I was going on the assumtion that running at 1/4 throttle for a bit and the checking the plug was good for a pilot test but you seem to say it is not. Thanks
  7. Rich Rohrich

    Rich Rohrich BioHazard

    Joined:
    Jul 27, 1999
    Messages:
    22,269
    Media:
    6
    Featured Threads:
    5
    Likes Received:
    10,942
    Trophy Points:
    1,325
    By feel or with a wideband oxygen sensor connected to a data acquisition system that also reads throttle position.
  8. Jaybird

    Jaybird Apprentice Goon

    Joined:
    Mar 16, 2001
    Messages:
    7,099
    Likes Received:
    0
    Trophy Points:
    36
    As always, you are most enlightening, Mr.
    Thank you.
  9. Rich Rohrich

    Rich Rohrich BioHazard

    Joined:
    Jul 27, 1999
    Messages:
    22,269
    Media:
    6
    Featured Threads:
    5
    Likes Received:
    10,942
    Trophy Points:
    1,325
    Mister™ is a registered trademark of billywho™. All rights reserved. Portions ©2002, billywho™. Unauthorized use is a no-no.

    Careful Jaybird or BillyWho will send the black helicopters to pay you a visit :scream:
  10. Jaybird

    Jaybird Apprentice Goon

    Joined:
    Mar 16, 2001
    Messages:
    7,099
    Likes Received:
    0
    Trophy Points:
    36
    I think he's got his infringement lawyers looking at it now. I only used said term once before and it was immediately noticed.
    I agree, a man needs to be careful! :eek:
  11. whyz

    whyz Subscriber

    Joined:
    Nov 18, 2001
    Messages:
    480
    Likes Received:
    0
    Trophy Points:
    0
    Thanks for a very good start of my day.
    You guys are way too funny :)
  12. whyz

    whyz Subscriber

    Joined:
    Nov 18, 2001
    Messages:
    480
    Likes Received:
    0
    Trophy Points:
    0
    So with Dave's plug..
    Do you think that ridin trails and MX,that this plug would be too rich?,
    And can you tell by the look of the plug what type of riding the plug was being introduced to?? (just an opinion please) :silly:

    Thank You.
Similar Threads: Plug reading
Forum Title Date
Technical Posts the 'R' in spark plugs Jun 3, 2002
Technical Posts Cutting open plugs for jetting (pics) Oct 25, 2000

Share This Page