Spark Plugs, which ones?

[CRXSi90]

My motorcycle is running NGK BR6ES right now.

The manual calls for NGK BP6ES.

See the difference? I have R, but P is called for.

BR6ES
BP6ES

If I read their info right, the plugs are the right size and all, with slight differences.

BP6ES plugs are Japanese Industrial Standard height. Also, they have a projectile tip (slightly extending, I assume?). Those are what I should have.

BR6ES plugs have resistors. Thats all. Thats what I have

So who cares? Which one should I get? Do my plug wires already have resistors? Do I need resistors for the bike to function (not interfere with other ignition stuff or whatever)? I have a radio on the bike. That would be interfered without a resistor, right? Do I have a resistor, or do I need this self-resistored plug?

LOL, I'm sure I sound frantic and like I've lost my mind! The last part may be true.

Thanks so much, guys! I don't know what I'd do without you!

kevin

[pgg]

CRX, that BR plug is a 2-stroke resistor plug. A BPR plug is a 4-stroke resistor plug. The projecting tip is better for 4-strokes because the intake valves' fuel/air flow cools the plug.

[Pat Kelly]

I'm running Bosch Platinum 4218 in mine (with Dyna coils).

[UncleSpot]

...and I'm running Bosch Platinum 4216 in mine - '80XS1100SG stock except 4-into-1/Kerker/SuperTrapp

Pat, what's the difference b/w 4218 and 4216?

[Pat Kelly]

I think mine are one step cooler than yours. I have the Jardine 4 into 2 exhaust, K&N filter in aribox, Dyna coils (42,000 volts comapred to 12,000 volts for stock coils), Silicone wires and MSD plug caps. I have my air/fuel adjusted slightly rich (using a colortune). My exhaust pipes aren't blued but I lack power on the few occasions I ride above 5-6,000 feet elevation.

[TopCatGr58]

Hey there 90,

Yes, the plug caps have resistors built into them, ~5kohms. Theoretically you can run Non-resistor plugs, but like you said, you may get more RF interference from them on your radio!

Follow this link for a list of plugs that you can use on your XS!
List of Plugs Tech Tip
T.C.