HMF / My spark plugs

srx2002 · Oct 13, 2007

Hi folks, I just installed my new HMF on my 06 max, it has 100 % STOCK carbs, with a K & N replacement filter. It seems to run fine. However I am unsure if she is running rich or lean...it''s really hard to tell ...so I snapped a picture of one of my plugs for all the Carb Air/fuel Guru's out there. ( all plugs are the same )

Please tell me what you think ( I have seen some plug charts on the internet, however I'm still unsure )

conditions:

Sea level
about 5 degrees above freezing

P.S Does turning out the Mixture screws increase the airflow ..therefore leaning out the a/f mixture...or do I have it backwards? ( they are presently untouched factory set )

maleko89 · Oct 14, 2007

Lean. Shoot for a grayish...either light or dark color. Turning mixture screws clockwise, leans....counterclockwise richens.

Mark
#1098

srx2002 · Oct 14, 2007

From that picture of my plug, I'm lean? or just right?

vmaxinID · Oct 14, 2007

maleko89 said:
Lean. Shoot for a grayish...either light or dark color. Turning mixture screws clockwise, leans....counterclockwise richens.

Mark
#1098

srx2002 said:
From that picture of my plug, I'm lean? or just right?

:coolgleamA:

113s&s · Oct 22, 2007

color look great to me

Lew L · Oct 23, 2007

In a strong light --- look down the insulator and you should see dark or tan ring down in the recess of the insulator. If its about half way down, your good.

Also with a magnifing glass check the electrode very closely. There should be no rounding or softening of its edge after a few full throttle blasts.
By the looks of the other parts of the plug, looks like the low end is a bit rich( carbon deposits on the threads).
But,My heart tells me the insulator looks a bit lean. So raise the needle with a washer( about 0.025" thick) and sync the carbs.
Good luck,
Lew