Listen to RYU. You are getting a HORRIBLE DEAL!! I know you just want to get a ride and are jumping on the first deal you see, but there is a working version out there for that price. Look longer. Annoying I know, but you will get a better deal I am sure. You are assuming that the engine is all you need, but the engine is the bullet proof part of a Kawasaki. If you are having to replace the engine on an 8 year old Ninja, I am pretty sure it was completely thrashed and NOT cared for at all.
Good luck and ride safe.
Good luck and ride safe.