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11 250 plug color

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just figured id have a look,my bikes got a full yosh,air4force airbox(short snorkel),screen removed and Throttle body insert.running 94 oct chevron with no ethanol. temps have been pretty much freezing right now and still riding at the track.it has one of eddies maps in it.The color actually looks whiter in person.plug has about 6hrs use on it.

it starts 1st kick right now in this dead cold after a couple prime kicks,runs really well but just wondering how the color compares to what others have on the newer bikes.

plug_8.png

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Looks very similar to any perceived properly running 4 stroke. Going off of color on a 4 stroke is just short of useless. It is generally the additives in the fuel that make the color and in a 4 stroke there are far less additives in the fuel than a two stroke.

In years past with two strokes it was so important to have the proper ratio of fuel to air because the reciprocating mass was oiled by such a mixture and the easiest sign was the plug due to the oil mixed in the fuel. With a 4 stroke the fuel to air ratio is not so important in this matter because the reciprocating mass is oiled from a sump and oil pump.

Now, certainly HP and longevity will be affected by a poor tune but this is almost impossible to tell by the color of the plug alone.

There are other ways to tell rich or lean and still use the color approach. Look at the exit of the exhaust, top of piston, combustion chamber, and operating temp. Same rules apply, dark is rich and light is lean. Seat of the pants is also another good test if you have some experience stored in your brain. Short of an exhaust gas analyzer and a good microscope these are your options.

An important part of plug inspection on your 4 stroke is overall condition. Are there blisters on the insulator or small indentations on the electrode, these are signs of pre-detonation. If you search the web you will find lots of good info. Check out the link to get you started.

http://www.procarcare.com/includes/content/resourcecenter/encyclopedia/ch07/7Fig12.html

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i.m.o. its to ritch , a 4 stroke spark plug from a dirt bike is difficult to read , buth i.m.o. the outher ring of the plug is to dark . when you lean the bike you will see the iner and the outher of the plug wil getting a light brown (tan)collor . a had the same plug with a dark outside and a light center and when i make it richer it has no effect, than i set it leaner and yes i have a overal light brown collor

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+1 on being a bit rich. You have to go by the outer ring with these 4 strokes on not so much on the insulator color.

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