have spark but won't run

[nottuskram]

Hello I took my boat out and the motor was running and then it went to half speed.I thought that i fouled a plug.When I took the cover off and pulled the 3 cylinder spark plug wire off the metal insert was broken.Powered in on two plugs.I got a new end and the boat wont start.Yesterday i check everything for spark and found the 2 cylinder was not sparking and replaced the coil (CDI) and now I have spark in all 3 cylinders.So here is the deal that i have now.When I turn the key it will start and quit once I let go off the key it quits.it is a 90 and i belive the date is 1985
Thank you Mark