Its alive! Barely, but it makes noise. I think it'll run fine once I get the rest of the pieces on there and tune the carb. Here's a video of it running. This is with the WT-194, btw.
If you watch, you can see a screw pop off when I first rev the saw. This is where it came from.
I guess I'll have to drill and tap the hole. I don't think I have a tap that small. Hopefully there's one at the shop.
I thread insert (helicoil, timesert) will be more durable than hogged out magnesium threads.