Aaron is right - I am running a Mercury Optimax 200. I've been told it's a GM engine but don't know for sure. Because the 4 beeps would stop and take so long to come back, I continued to run the engine only to get it home (about 20 minutes). It didn't matter what speed I ran - the interval was the same. Had the beeping never stopped, I would have immediately shut down the engine and called SeaTow (my buddies).
I was running up the coast in the ocean when the beeps started. I immediately headed to the first ship store I could find (about 10 minutes away) and got 20 gallons of ethanol free gas and a gallon of Quicksilver oil that I've always used. Even though I visually check the oil container before going out without fail, I didn't want to take any chances that it was my lack of attention that caused the problem. I guessed that if either of those were the cause the beeps would disappear. The beeps continued.
I haven't had a chance to check the oil reservoir on the engine yet (my son in law is going to Afghanistan and we spent the past few days there seeing him before he goes) but I am pretty sure that during my visual inspection of the engine that it was low. I remember thinking it was unusual but thought maybe it was because it hadn't been run in about 10 days. I am hoping that filling that reservoir is the solution because then my problem would be solved. If not, I am capable of checking the continuity as you suggested. Either way, they both seem to be inexpensive fixes (finally!).
But I have to know more (sorry). What would cause this to get low? Is there a pump somewhere that keeps it full? Would low oil level in the main tank contribute to causing this? Is this something I should add to my visual inspection checklist of the engine area before I take it out, or should I check it every third time (or other interval)?
I have a couple other performance issues and get the impression you are likely a mechanic or other techically based 'expert'. I would like to run another problem by you to see if the local Merc dealer was trying to rip me off or if their explanation of a problem is correct via email if you don't mind. If you prefer for me to open another ticket, I can gladly do so.
I have mechanical knowledge and experience but have no idea what I'm doing when it comes to marine engines, especially my SeaDoo. I had my Kaw Jetski for 9 years and never had a problem with it so I guess I was a little spoiled.
One last question: how come getting the beep codes for the different models is so difficult for everyone? Is it in the manual and I missed it?