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I just changed out new spark plugs for my cm400t and wasn't too sure how to read the old ones to indicate my engine's condition. Any help to why the threads have oil on them? 20191018_175111.jpg 20191018_175046.jpg
 

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They both look acceptable to me but they should match better IMO. Are the carbs synched?
 

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The one with the more white ceramic is close to right, should be more so. The other is a little more rich.
The oil on the threads is due to the plugs not being tight enough. Note the difference in the crush/seal washers. The plug with oil all the way up also shows it creeping past the washer plus it's thicker than the other one. The plugs actually have a torque spec of 11-14 ft.lbs.
 
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