StromTrooper banner

differennce between hot spark plug and cold spark plug

3K views 3 replies 4 participants last post by  saturn 5 
#1 · (Edited)
A spark plug is said to be "hot" if it is a better heat insulator, keeping more heat in the tip of the spark plug. A spark plug is said to be "cold" if it can conduct more heat out of the spark plug tip and lower the tip's temperature. http://www.ngksparkplugs.ca/tech-info-spark-plugs.cfm
 
#2 ·
And the bonus question is... How can you tell when your existing plug is too hot or too cold??
 
#3 ·
In a liquid cooled bike, heat range isn't as big a deal as on an air cooled bike. Liquid does a much better job of removing heat from the combustion chamber, allowing a wider heat range on plugs. That being said, too hot a plug will erode electrodes too fast. In extreme cases, it can cause hot spot detonation or even pre-ignition. Too cold a plug will foul as it won't burn off deposits properly.
 
#4 ·
Too hot a plug will show pitting on the ceramic central electrode and will be colored white-ish gray, too cold will burn sooty. The color to aim for is light tan/gray with the tip looking clean. Lots of color images available with a little searching. Look up NGK or Denso.

Saturn 5
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top