Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1

    Join Date
    Jan 2017
    Location
    Raleigh, NC
    Posts
    31

    Spark plug color advise/feedback

    Hello all,

    I need some feed back on the color of my spark plugs. I have them tuned a out a bit on the rich side both high and lows but want to make sure i'm not running lean. Pictures were taken right after running at WOT and pulling the lanyard. Engine is a Yamaha 701 twin carb.







    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	unnamed (1).jpg 
Views:	55 
Size:	24.3 KB 
ID:	410008   Click image for larger version. 

Name:	unnamed (2).jpg 
Views:	58 
Size:	28.5 KB 
ID:	410009   Click image for larger version. 

Name:	unnamed.jpg 
Views:	65 
Size:	36.5 KB 
ID:	410010  


  2. #2
    Personally from the pics Id say a bit lean. The ends look white/grey on pictures.

  3. #3
    I'd say lean too. I used to have plugs a similar color and it leaned out too much on a cool morning. Better safe than sorry imo.

  4. #4

    Join Date
    Jan 2017
    Location
    Raleigh, NC
    Posts
    31
    So I should back out the high speed jets a 1/2 turn or so?

    I also for got to mention these plugs only have about 2 hours of run time on them.

  5. #5
    I'm not familiar with the 701 setup but if it's like mikuni carbs in the GPRs then yes, the high speed screw we would be the place to start as it controls fuel flow at full throttle. Make sure to do some plug chops in the mid range as well.

  6. #6

    Join Date
    Jan 2017
    Location
    Raleigh, NC
    Posts
    31
    Thanks for the response. I wondering why its still running lean? Stock spec calls for highs to be set at 5/8 on the PTO and 1 1/8 on the mag side. both highs are set @ 2 turns out and it runs great with great throttle response and no bogging.

  7. #7

    Join Date
    Jan 2017
    Location
    Raleigh, NC
    Posts
    31
    Another thought will running synthetic 2 stroke oil cause the plugs to appear leaner than they actually are?

  8. #8
    Myself's Avatar
    Join Date
    May 2007
    Location
    North Central Arkansas
    Posts
    3,368
    +1
    193
    No, but running oxygenated race fuel will.

  9. #9
    If it runs great leave it as it is. They run lean at factory settings. They are only slightly lean looking them and may only give you issues if you held it at full chat for very long periods.

  10. #10

    Join Date
    Jan 2017
    Location
    Raleigh, NC
    Posts
    31
    Ok thanks.

    My next thought is to just re-jet a size bigger and go from 1.2 to 1.5 needle/seat and see if that helps.

    I currently am running 120 mag/130 PTO highs and 67.5 lows. I would re-jet to 122.5 mag/132.5 PTO and 70 on the lows.

    Let me know what you guys think.

    Thanks!

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Spark Plug Color
    By Tedcfitz in forum 4-Tec Performance
    Replies: 14
    Last Post: 11-01-2015, 11:09 AM
  2. help with spark plug colors on rxt 215
    By 4pinwink in forum 4-Tec Performance
    Replies: 21
    Last Post: 06-20-2012, 07:08 AM
  3. Virage i 800 Spark Plug Coloring
    By lilman573 in forum Polaris Open Discussion
    Replies: 1
    Last Post: 07-26-2010, 09:17 AM
  4. stock spark plug color at idle
    By ou812 in forum 4-Tec Performance
    Replies: 3
    Last Post: 04-22-2007, 11:21 PM
  5. spark plug color/texture
    By MDGPR in forum Yamaha PWC Performance (2-stroke)
    Replies: 1
    Last Post: 04-12-2007, 10:14 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •