I am looking at a 94 cavy. It will not start but you can hear the starter engage. Had a cylinder head and water pump replaced less than 500 mi ago. I have yet to look at it, my friends brother has it. I am just curious if anybody could know what it could be.

Fuel pump would be my guess... But there is a number of things that can happen. So don't take my word for it.

if it doesn't turn over the starter is dead. lay underneath and hit the starter with a heavy hammer while someone thries to turn it over. if it goes then just replace the starter. Pretty quick job, depending on debris I can do one in ten mins without rushing!