Make Sure You're Not Buying Scrap Metal

Something I haven't talked about (which I probably should have) is making sure you don't buy junk. If you're buying a used motorcycle (crashed or not) you run the serious risk of biting off more than you can chew. You need to make sure that you can scout the tell-tale signs that a motorcycle is junk or is going to cost you a lot to fix:

• Bad Forks
  The front end should bound and rebound without resistance. When compressing the front end, you shouldn't feel it catching at any point. The motion should feel fluid/smooth. If the suspension catches or bottoms out, you may need to replace the forks or have them rebuilt. Most superbikes run a cheaper suspension to offset the cost of other components and increase profit (It's not necessarily a bad thing: Most superbike suspensions these days are pretty good anyway). The benefit to you is that it shouldn't cost a fortune to replace them. If you run across an Ohlins suspension, don't throw it out if you can get it repaired -they're well worth it. Do your research first! The downside is that this might mean you'll also need a new front wheel, brake components, and tripple tree. It all depends on the damage/crash.
  
  Make sure the seals aren't leaking. Seals can go bad from the bike sitting for a while. You'll see oil develop/leak down the fork after it sits for a little while (assuming you have "inverted" forks). For most forks, you should be able to find a shop that will rebuild them. Again: do your research. The cost will be more in labor than in parts.
  
  More obviously, make sure the wheel points straight forward when the handlebars are straight and that it's not damaged (along the rim). The brakes should work properly without a hint of odd behavior: pad wear should be pretty even. Uneven pad wear could be a sign of a seized caliper. If you're a good rider and not likely to crash the bike immediately, insist on a test ride (obviously you'll be required to buy it if you dump it so don't screw around).
  
  
• Bent/Damaged Frame
  Frames may end up bending/twisting through use, but in very very minor amounts. You want to look for bends caused from a crash. Look for scrapes or gouges from a hard crash. On a Ducati, you have a trellis frame: basically a tube frame. If there's significant damage to a part of the frame, the tubes could be dented in. This is a pretty serious problem; you'll need to replace the frame.
  
  Look for fractures around the seams: Cracks or bends in the frame where the foot pegs mount, where the engine is bolted to the frame, etc. Small fractures in a frame could lead to catastrophic failure when you're on the track. Don't risk it.
  
  Scrapes and scratches usually show the bike went down, but they might not be an indicator that it was severe. Look the frame over closely to be sure.
  
  
• Chain & Sprockets
  You might be able to get some idea of how the bike was ridden (and maintained) by looking at the chain and rear sprocket. If the bike was wheeled a lot or the throttle was abruptly jerked repeatedly, you'll see kinks in the chain. Additionally, the rear sprocket may have become hooked.
  
  
• Engine
  Have the bike run and warm up. Rev the engine and make sure that blue doesn't come out of the exhaust. Blue smoke is a sign that the engine is burning oil. You're looking at a rebuild (in some degree): Big money.
  
  Obviously, the engine should rev smoothly and not sputter.

Those are really the major things to look for: The core components that can lead to costly repairs. Most of the remaining parts; handlebars, plastics, lights (which you don't need/want on a track bike), foot controls --these components are very often the first things you remove or replace on a track bike.