Reading spark plugs

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(Changed affect to effect since it was a noun)
(Amended picture description to alleviate confusion between detonation and pre-ignition and to provide the correct remedy for the problem.)
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[[File:Rich18.jpg]]
 
[[File:Rich18.jpg]]
  
Black or brown specs: This is an indication of detonation usually caused by a heat range that's too hot. The plug gets so hot that it will start to detonate the fuel before the ignition fires, this cause a double flame front and reduces the efficiency of the combustion process as these two flame fronts collide with each other.
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Black or brown specks: This is an indication of detonation which is caused by ignition timing that is too advanced for the air/fuel ratio or octane of the fuel. Detonation (an undesirable, uncontrolled combustion of the air/fuel mixture after the ignition event) causes the boundary layer of air within the cylinder to be disrupted, which in turn causes the components and surfaces within the cylinder to absorb heat from the combustion process and increase in temperature. The black spots are the result of oil deposits bypassing the piston rings during detonation and being fused onto the porcelain by the increased cylinder temperatures. Tiny beads of grey/silver material apparent on the porcelain are melted piston. Reduce the ignition timing, richen the mixture, increase the octane of the fuel or a combination of all of these to prevent this situation.
The black spots are the result of the fuel deposits being burned onto the porcelain by the double flame front. Go one or two heat ranges colder and it should go away.
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Once you correct the plug heat range which removes the secondary ignition source, and/or address a lean air/fuel mixture, you can reset the total timing for optimum power.<br>
 
 
{{Warning}}Do not underestimate the damage this condition can cause your engine. Correct this by whatever means necessary.
 
{{Warning}}Do not underestimate the damage this condition can cause your engine. Correct this by whatever means necessary.
  

Revision as of 17:56, 7 June 2020

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