Well, second gear isn't useful anyways right?

After all the help from everyone, I have a running KZ1000K that still needs a ton of work, but is at the very least: Drivable. When I found out that second gear is completely non-existent. I've been lurking around reading post after post and it seems that pulling the engine is the only way. I would like to say thanks to you all though for the information needed and letting me know that I will need at least a case of beer or so to do this messy job. On a sidenote though, it doesn't hurt anything to just shift from 1st to 3rd and ride it like it is right?

Not if u keep the load down so that u are not lugging bad when u let the clutch out into 3rd.
just change from 1st at a higher rpm then 3rd will be happier.
it will be a little harder on the clutch plates (they will ware faster) but it should not be a big deal. as long as u are not creating a ping or severe load when u start to accelorate in 3rd.

Second is non existent?

Are you sure your just not missing the shift drum pin?

For KZ900 as example....

Hopefully it is something simple, as the shift drum pin described above.

However, if you just obtained the bike and don't know it's history, it's possible some teeth are missing due to shock when "popping the clutch". Ask me how I know this.

If the debris has fallen to the bottom, you might be lucky enough to drive it, provided you don't hit a pothole/bump which might reingage that debris in the gear train. Then you might be looking at some really expensive repair, if repairable at all. Again, ask me how I know this.

Do what you feel comfortable with.

Second gear is the weak link. If you have to replace it, don't use stock gears. kzzone.com/trans.html

for a little peace of mind, you could drop the oil pan, and have a Look/See