glad you brought that up, as a quick look in my downloadable manual here.....
http://www.rydindirty.com/blastermanual.pdf
on page 44 it calls for a "D8ES" for the US. and a "DP8ES" for canada and africa
misprint ???? we all know that "D" is wrong
a quick ebay search will result in both B8ES and BR8ES plugs
and the general consensus on here is to run the "B8ES" not the "BR8ES"
the "R" is just a resistor plug, and has to do with less radio interference,
and anything with a resistor involved reduces voltage and possibly the spark too ???
the NGK website calls for the "B8ES" for our blasters .....................
http://www.ngksparkplugs.com/part_finder/atvs/step4.asp?id=737&type=reg
heres NGK's explaination of a resistor plug, and it's uses...........
FAQs - Spark Plugs
Q: When should I use a resistor spark plug?
A: NGK "R" or resistor spark plugs use a 5k ohm ceramic resistor in the spark plug to suppress ignition noise generated during sparking.
NGK strongly recommends using resistor spark plugs in any vehicle that uses on-board computer systems to monitor or control engine performance. This is because resistor spark plugs reduce electromagnetic interference with on-board electronics.
They are also recommended on any vehicle that has other on-board electronic systems such as engine-management computers, two-way radios, GPS systems, depth finders or whenever recommended by the manufacturer.
In fact, using a non-resistor plug in certain applications can actually cause the engine to suffer undesirable side effects such as an erratic idle, high-rpm misfire, engine run-on, power drop off at certain rpm levels and abnormal combustion.