Spark plug Bosch or NGK

NGK Iridium, it’s what I get about everytime.

Recently got the following parts: Racingline VWR Springs 034 Motorsports strut mounts, new bearings and bump stops Rear strut mounts with new hardware and bump stops Deautoled LED license plate OEM Autodimming rear mirror with wiring harness APR boost tap NSP boost gauge with vent Hella oil level sensor Oil pan w level sensor European Headlight Switch APR Coilpacks Spark Plugs NGK BKR8EIX R LINE CENTER CAPS

Just changed mine out for the second time 2012 w/ 172k. Misfire engine code. NGK iridium. Getting 10 more mpg. Best 50$ I’ve spent in a long time

I went with Bosch but you really can't go wrong with the 4 vendors you have listed.

Iridium will last longest. Grab them if you race or run the piss out of that bike but for all intents and purposes a plain old NGK is plenty adequate for everyday riding and then some.

Ngk have been pretty reliable motor craft is pretty good too but I've seen good life spans for both.

Very broadly, only use NGK, Denso, Bosch, or Champion.

I recently just replaced my spark plugs they were past due. So I bought the OE Bosch 9683. The engine runs fine, starts easy, no misfiring, no rough running. But after the plug change I am getting much worse millage.

Went through both ngk and autolite, didnt like they're spec'd plug for it.

Most imports (To the US) don't like anything but NGK/Denso.