I just changed out the plugs and the one from the rear cylinder looks so much worse than the front. They are the ones that were in the bike when I bought it, but I assumed, and I know I shouldn't, that they would have been both changed at the same time. I know the rear cylinder runs so much hotter but this seems a bit of a extreme difference. Any thoughts?

 

Orher than the corrosion on the outside, I don't see much difference between two of then.

 

True, I am wondering if excessive heat caused the corrosion? The tip of the plug was slightly more "burned" than the front one. It was powdery and dry where the front one had a greasier feel to it.

 

I have never seen that, but, the first thing I do when I buy a new (to me) vehicle
is to change the plugs and oil(s). Since your bike is an '07..not knowing how long you have owned it.....it was probably due for plugs. Now you can monitor the plugs, and heck.....change them in six months if you want. LOL

 

I have pulled them out that were rusty like that one. Symptom of living on the coast. They both look like they are burning great though. I am like Chuck when I get used vehicles I change everything just so I know its been done and when.

 

Thanks guys for the input. I normally would change them also but they told me they just did the 20k service so I assumed they had been changed. But as was already said, at least now I know and can keep a eye on them

 

Don't know if it would make that much of a difference, but the rear plug gap is looks to be bigger. Maybe it IS or was running significantly hotter.