Nothing to worry about, that's normal. The reason it's so long is to get down to the combustion chamber through the full length of the head. Being it's an overhead cam motor, it's gotta go a LOT further down to reach the sparkplug than say, a lawn mower. If it runs, you're golden. Worst that'll happen is you'll get a misfire, which will just feel like a studder/ rough idle. Just make sure when you push the plug wire down the hole that you get a feeling like it snapped or clicked into place at the bottom.
We're glad to help with whatever you need!!
We're glad to help with whatever you need!!