Stumped. Spark, compression and fuel. Bike no run.

My wife's 77 KZ 400 was running just fine last year when she tipped it over and popped a hole through the clutch cover. I had to remove the ignition timing system to replace the cover, and when I put it all back together, the bike wouldn't start.

I"m following the manual's directions, setting the points gap and aligning the "F" mark with the opening of the points. The plugs are sparking. There's compression. I sprayed starting fluid in the carbs, so there's fuel.

The only thing that seemed weird was that the "F" mark arrived at a point of rotation where it was really easy to turn the crankshaft, leading me to think that it's sparking when the piston is down and there's no compression in the cylinder.

What am I missing?

You have spark to the plugs when they are removed and laid onto the head, with the plug wires connected of course, kicking it over? Sounds like you may just have a dirty set of contacts on your points set. Did you replace those or just put the old ones back in? If the old ones, they would have a bit of pitting and build up that can effect the gap when you use a feeler gauge. SO do you have a dwell meter? Thats the best way to set the points. If you don't have a new set, a points file can clean them up, reset the gap/ dwell and try that.

When working on the bike did you remove the advancer? If so then there's an assembly note in the manual (see kz400.com) regarding lining up a mark with a notch
Might be worth a look?
just a thought.

The plug is sparking when I pull it out and rest it against the engine case while trying to start it. I didn't replace the points, but I can't imagine why it would run pretty well before removing them and then not at all after.

I'm not sure what a dwell meter is. I set the gap using a basic feeler gauge.

I'll check kz400.com to see about that notch/mark note for the advancer.

If you removed the ignition cam from the advancer make sure you put it back correctly. Here's how:

www.armbell.com/kz400/viewtopic.php?t=3177&mforum=kz400

Does it try at all? Cough, Backfire, spit out the carbs?