Spark plugs. Again but different

[Defender88]

so my front plug looked great. nice mocha color, but my rear was pretty white. not bad but I can tell its running a little lean. Is this normal for the rear cylinder. I just switched from the factory HD plugs to iridiums

 

[Defender88]

I know I just put this post up but I want to make sure this is safe to ride. and perhaps a solution to this

 

[Defender88]

bueller?

 

[Stevenc150]

It's hard to say without actually seeing the plug. -Spark Plug Diagnosis

 

[Miami78]

My front runs richer than my rear, too. When I pulled my plugs last my front looked like the dry fouled example in stevenc150's link. Just put iridium in as well, but the expert I'm talking to from EBR has suggested a hotter plug for the front.

 

[Kruger]

Miami, please elaborate. I just purchased a 2007 XB12S and would love to know what exactly he recommended. I'm looking through the old spark plug threads now but would love some fresh information.

 

[Chicknstripn]

You're asking for info on a six year old post!
Don't think you're gonna find anything fresh there!
Here's something not so fresh but relevant us NGKs.
Can't recall the exact part number but most recommend the 9s over the 8s.

Another tip.... ....don't rev your engine when it's cold or on start up. That's a guaranteed way to foul out ANY plug that's in your XB.

 

[GregoXB]

Install an RSS, this helps keep the rear cylinder cooler.