Re: need help badly
Need to check Thermostats, Water pump and Water Deflectors if your engine has them.
Go here to get an overview look of your engine.
http://epc.brp.com/default.aspx?brands=ej&lang=e
Take off stat housing and look for obstructions, and check to make sure they are opening correctly. Clean and replace or get a stat kit, they are cheap
Do a water pump overhaul or atleast a impeller change. Video example..
http://www.meegsonline.com/tmd/waterpump.wmv
Lastly if you do have water deflectors, feel which bank is getting hot, then pull head off to inspect passages and deflectors.
http://forums.iboats.com/showthread.php?t=199287
Someone having simlar problems, read the example I put in there.
Also for future refernce if the alarm is going off shut her down, dont continue to run and cause possible damage.
Best of luck, pm or post back results and any other questions you have.