Spark plug?
 

I have just changed my spark plug. EC200 2005. It had a B7 ES in it where as it says it should be a BR8 EG. The bike has been running great, starts easily even after an off. What is the difference and basically what should I do, Stick with what was in it or change to standard?

The 7, 8, or 9 ect. denotes the heat range. If it is jetted correctly the 8 should work perfectly. Some try hotter or colder plugs to compensate for incorrect jetting but that practice is really not a good idea.

The "7" is one heat range hotter than the original and the "ES" is a standard electrode material where as the "EG" is platinum I believe (going from memory here). The "R" means it is a resistor plug which helps eliminate radio and other electronic interference. Like Lankydoug said, some guys will use a hotter plug to try and avoid jetting a bike properly or cover up other mechanical issues, but it should run best with the factory recommended heat range unless heavily modified. Here is a link to a good explanation of heat ranges:

http://www.championsparkplugs.com/ch...?kw=Heat+range

Wes.

"EG" is standard material small electrode, aka the Race Plug. "EIX" is iridium. Some times you can find the odd ball almost never used "EGV" plugs that are V-groove platinuims.