Weeping and gnashing of teeth (Miata content)

I am busy and a bit of a Bob Costas about working on cars in the cold, so I just paid a buddy to install a dealer-sourced Mazda Value Products clutch kit and NAPA flywheel in my '91 Miata. This guy is a GM technician and a Miata enthusiast and I trust him, and he did the work at the dealership. The new clutch works great, but ever since the clutch job, the starter emits a gearteeth-grinding noise when I release the key. It's weird: I turn the key, the starter engages normally with no odd noises or behavior, and when the engine fires and I release the key, that's when I hear the noise - it sounds just like it would if you tried to start an engine that's already running.

I examined the starter mounting bolts last night and everything looks perfect. All bolts are tight, including the ones on the bracket that mounts to the block.

The starter is the original. (I have all receipts since this car was new.)

Could this possibly be my buddy's fault? Is it just an odd coincidence that the starter is failing now?

I would bet the teeth on the NAPA flywheel are staying engaged to the starter, causing the noise. This may be one of those "allow parts to self clearance" problems. Unless Miatas have starter shims, I think it's not your buddy's fault.

Yep, the flywheel is causing the problem.

Your diagnosis makes perfect sense. And because the gearteeth mesh fine, and then the noise happens when they separate, it's probably unlikely that any damage will result. The parts will probably "self-clear" as NONACK said. Thanks a lot, you guys. I will stop worrying and won't bother my buddy about this.

Well, I'll risk going a little counter-flow here. If the starter gear is staying engaged, you're spinning it up wildly high with a running engine. Things can grenade as a result. Probably won't be a spectacular grenading, but if bits go in between the flywheel and bell housing in the process...

In reply to foxtrapper:

If it does it continuously yes, I got the impression this is a few seconds after starting. Maybe I'm reading too much into it?

It's a split-second grinding/scraping noise that happens during the instant the engine fires and I release the key. I really wish I had talked my buddy into reusing the original flywheel, but he felt that after 110K miles, I'd be better off with a new FLAPS flywheel. I'm now wishing I'd sprung for the Flyin' Miata flywheel and clutch assembly. Penny wise and pound foolish, I guess.