Ok, here we go. My 09 Bolt is getting near 10,000 miles so I dug out my factory manual and watched some of the Do It Yourself video's and got started. I thought I would start with the plugs. Bought the NGK Iridiums like everyone suggests. By all indications the front plug is easy the rear is the bitch. Well not at my house! The rear was easy but the front was a pain. The video shows coming at the front with the 6" extension and a swivel. My swivel would not work on the front(too much angle?). So I came at the front plug, with an open end wrench, from the side of the bike. It works, just takes alittle time. Too make a long story short, I can't believe the difference these plugs made! The responsiveness of the motor and the easier starting is outstanding. I don't mean to sound like a commercial but I am amazed. The stock factory plugs looked fine(since this is my first EFI engine I have lots of years of tuning my carbs, you do know what a carb is, don't you?). Maybe I just got to being used to the Harley plug performance but it's worth the work. For those of you who have someone else work on their bikes, go buy some wrenches and do some of the work yourselves. I really had a great sunday performing these simple tasks and enjoying the results of my simple work. Forty years of garage tinkering and I still amaze myself(at least sometimes). Maybe a thanks to NGK should be done also. Oh, some beers after this work tasted great!