any ideas, I have twin efi 525's. starbd engine idles at 700, drops to 200, revs to 1200 and alarm goes off. Back to 700 idle then same scene again. went home on port engine. Any ideas ? Thanks in advance.

You could have some fuel feed problems. Change you fuel filter and If I am not mistaken the 525efi's have no filter between the tank and the primary pump on the cool fuel system, unless your boat builder was good enough to install one. You might be sending some debris right from the tank to the first pump. If it turns out not to be fuel and you can rev the motors up under load with no problem, I would have someone hook up the Merc or Rinda scan tool up and read trouble codes. Good Luck, hope this helps.
Raylar

Thanks for the input.