I did a quick 'n' dirty compression "test" when I checked out the car in Montreal:
1) Got a baseline: I know the Flea has spec compression, so I put it in 1st gear on level ground and released the parking brake.
2) With the door open, I pushed against the A-pillar until the car moved a little. I had to push pretty hard -- hard enough that I found I was holding my breath to make it lurch through each compression stroke.
3) A few hours later in Montreal, I repeated the procedure on the Y2k Metro. It seemed like a similar (high) amount of effort, which I did 3 times (once for each cylinder), so I decided it must not have
bad compression. Also it seemed to start up quickly, and had "normal" power (for a Metro).
Is that a valid way to check compression? I dunno.
But a pilot friend says he has used a similar technique to check propeller airplane engines.
Actual compression test done this aft with a proper gauge... and it's great:
1st set: 205 / 185 / 210
2nd set: 210 / 195 / 215
Woohoo!
(As predicted by the the DIY method and the stack of maintenance/repair receipts in the glove box that includes lots of oil change bills.)
Also, I discovered one of the spark plugs was loose! And by loose I do not mean "finger tight" - it was
loose. But all were otherwise healthy looking, and are only a few years old.
The distributor cap & rotor were disasters though: burnt/carbonized electrodes like you wouldn't believe. Last changed in 2003, if the stack of receipts is accurate. So I cleaned up the rotor, put on a new cap and it now it runs smoother & quieter (the tightened up spark plug might have helped too).
So now I'm even happier with this purchase.