1990 240 DL noisy start

[LikeAGloveBox]

It's making a loud knock on start. Usually a couple. It does start, but after a few times (this just started yesterday) it's taking longer. The next time I try to start I believe I should have a new part or be on my way to the shop. I already tried tightening the starter mounting bolts (although that upper one is hard to reach, so hard to tell how tight it is but I wad able to tighten it some). Is there any chance this is just a starter problem or at this point can I assume I need a new flywheel? I'm not up for that job myself, so is there anything else I can do to rule that out before I take it to the shop?

[LikeAGloveBox]

Well, it turned out to be the starter. The mechanic even took the time to go to Advance where my old starter was still under warranty, which I didn't even know(replaced 3 years ago at another shop), so less than $100 for his labor and I'm a happy fellow.