My jet ski won't start!

The other day I walked into my garage to start up my jet ski. It hadn't been run in about a month so I thought it was time to start it, as with all engines you need to run them every so often. Well, it wouldn't start, so I changed the positive battery cable leading from the solenoid to the engine. Now it won't even turn over, I have to debug this problem soon because I am going on a really awesome trip next weekend the second I get out of SAT's. I know most of you don't know what im talking about when I mention engine stuff. I just need to talk about something to get a good grade in Stoklosa's class.