Scooter Diagnostics Are Definitely Not My Strong Suit ...

... but I think I've 1) diagnosed and 2) repaired my problem. And if so, it was so stupid it was simple and vice versa.

I had this idea yesterday, but inclement weather precluded following up on it, so I did so this morning (I still hadn't had an opportunity to work with my mechanic on it -- previously he was ill, and this week some members of my household are ill and I don't want to risk getting him ill again by hanging out over there).

The question that came to my mind yesterday was "what if a replacement part I recently ordered and installed is defective?"

To wit, this "racing" CDI box (yes, even 50cc scooters have "computer brains" these days -- and no, that's not an affiliate link) that I bought because it's supposedly not RPM-restricted and I thought I might get some extra power out of the machine with it (there was no such obvious result).

So this morning I unplugged it, plugged the old CDI back in, cranked it up (it did take a couple of tries to start, but then it's 40 degrees out and the scooter hasn't run in three weeks), let it warm up, and took it down the block and back. 

It seems to be performing within normal speed/power parameters instead of topping out at 20mph.

Was it the new CDI, or was it something else? I think the former, but there's been at least one other big change since the last time I messed with it: Yesterday, the high winds knocked the whole machine over. So I suppose some chunk of filth in the carburetor might have gotten knocked loose or whatever. But I doubt it.

Once the day gets a little warmer, I'll take the machine out for a more thorough test.

I can't believe that didn't occur to me before I e.g. drained the gas tank and so forth.

Update, 9:23am: On one hand, I would have preferred to wait until it was warmer to do a more extensive test. On the other, it's not going to get very warm today, and I like to do this kind of thing when other family members are around to pick me up if the scooter breaks down or pick up my body if I crash it. So I just went out and did a somewhat longer run. Ran perfectly, with a top speed of 38mph (which is about what I've come to expect on that particular sub-one-mile stretch). So I'm provisionally pronouncing the scooter cured of its illness.