Spark plug colour

dj.chicken1

New Member
Apr 28, 2012
7
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0
australia
okay this is what my spark plug looks like at the moment after doing a plug chop on full throttle

should i go leaner or richer i think i have to go richer?

photo is below
http://motorbicycling.com/picture.php?albumid=794&pictureid=4417
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,818
211
63
up north now
That depends on what kind of engine that came from....if it's a four stroke, it looks pretty good.

If it's a two stroke, it depends on which oil you are running and at what ratio.
 

multipaul

New Member
Mar 31, 2012
75
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Germany
It also depends on the proper heat range of the spark plug. Your looks quite good. It is surely not too hot.

To judge about the spark plug image, the engine should be switched off immediately after the ride. Let it cool, unscrew the plug and judge.
One minute of idling ruined the spark plug image.

Here is an interesting link about spark plug images collected
by Dave31: http://motorbicycling.com/showthread.php?t=24873

Multipaul
 

Pilotgeek

New Member
Apr 6, 2011
403
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Green Bay, WI
Looking at the base ring: You have a nice even build-up going all the way around. It's a little dark. The mixture is about right, but you could go a bit leaner if you wanted.

Looking at the ceramic: This also confirms a good mixture, and it's not getting too hot. You could possibly go a touch leaner if you wanted, but right now you're good.

Looking at the ground strap: It's about good, though you could go one heat range colder if you want.
 

Pilotgeek

New Member
Apr 6, 2011
403
0
0
Green Bay, WI
General Plug reading Rules:
1.You set your heat range from the ground strap (this is the piece closest to the piston).
2. You can do all the plug reading for jetting from the base ring (the base ring is what the ground strap is welded
to).
3. You determine detonation and timing issues from the porcelain. The porcelain shows pre-ignition/detonation
and will not accurately determine jetting/air/fuel ratios. DO NOT BASE JETTING DECISIONS ON THE PORCELAIN
COLOR.