New (to me) boat, with 200 hours on stock 496ho motor, and i've looked in the manuals, and haven't seen anything about this high pitched beeping noise....

anyone have any ideas...

My first thought was oil, I'd like to put my boat in and use it over memorial day weekend without any problems, so.... I'm thinking i'll just go buy a bunch of oil and a filter, drain the oil, and replace with fresh.

video of the beeping sound... as you'll see, it's only intermittant, and only at top speed... at first we thought it might be max trim warning??? my buddy was driving and had it overtrimmed most of the time

link: http://www.youtube.com/watch?v=8rj-hhR8QXs

Thanks!

Two things to check. Drive oil in the bottle. It needs to be full, if its low it will beep. It will also beep on low water pressure. Could be over trimmed and not getting enough water but, most likely needs an impeller. You need a scanner to know what it is for sure. the 496HO has multiple warnings and you need a scanner to check them.

It sounds like a temperature warning and most likely your impeller is gone and needs replaced. This happened to me last summer on my boat not long after i purchased it and almost overheated my boat before i realized what it was. The impellers go pretty fast when they go out completely.

Both are good suggestions. On your next ride, watch for your temp gauge. If it seems normal, I'd say its the oil level. When I ran in the rough with my old boat, the I would have the same issue.

I had the same problem but, the temperature gauge always stayed the same. I put in a new impeller and it fixed it. The thing is I had a scanner. I read the codes and Dustin Whipple here on the boards told me what to fix. I would have been shooting in the dark without the codes.
Here is that thread.
http://www.offshoreonly.com/forums/g...ble-codes.html

It's either heat or drive oil

You said it only does it at high speed. How many rpm's are you running? If your touching the 5100 mark, you might just be hitting the rev limiters. They will beep like that.

true

After watching that video, a couple of things come to mind. One, from the rooster tail and as quick as the revs picked up, from the sound, it was way overtrimmed, so probably bouncing off the rev limiter - that's what the beeps sounded like to me. There is no over max trim warning beeps. Just the mechanical trim indicator. You could trim the drive right out of the water and there will be no beeping other than the rpm limiter beeps and maybe a "kaboom" sound. Overtrimming the drive that far is hard on the driveline. Second, firewalling the throttle from basically a standing start and almost simultaneously trimming it to the moon is really hard on the driveline ... the next sound you could likely hear will be "BOOM" when the drive lets go.

I had the same problem drove me nuts. Checked everything that has been suggested here, no luck. Ended up being the ignition driver in computer module. Had to replace the computer (ouch) no more beep!