I was going over past maintenance records on my 2008 gl1800 and noticed that on the 16K bill it doesn't look like the Honda shop replaced the spark plugs. At least it doesn't look like they charged me for plugs. I currently have 26k on the bike and am wondering if there's any way to determine if they were actually replaced. If not, when should they be replaced?
I was planning on a visit to the shop soon.