Hotter/Colder Spark Plugs - What's the deal?

[benchfalco]

Can anyone offer some insight on the calibre plugs someone should be using/I should be using, and what the significance of a hotter/colder plug is.

I am (will be) running a '93 600 Kat with a vance and hines 4 to 1 exhaust and a carb with a stage 3 kit installed, with K&N Pod air filters. I'm wondering if the stock plugs (NGK DR8ES) are what I should be running or maybe something hotter/colder would be better suited --- why?

I'm looking for a little lesson as to how and why different 'heat' spark plugs are used for different applications.

Thanks muchly!!!!!

[The CyberPoet]

For the full answer, see NGK SparkPlugs.com - Spark Plug FAQ. This will explain exactly what heat ranges are and when you would switch from one heat range to another.

KNOW THIS:
In the NGK rating system, the higher the number, the cooler-running the spark plug will be (the more heat the spark plug will transfer to the head). The NGK heat number range is from 2 to 11.

Cheers
=-= The CyberPoet