Mercury 240 EFI high speed engine alarm

[Aquaman1]

I have a 2004 Sea-Doo challenger 2000 with the mercury 240 hp EFI M2 Jet Drive. Here is my problem. When I idle out of the marina it runs fine. I go to throttle up no problem. Throttle up and get on plane then in about 20 seconds the buzzer alarm goes. It alarms for about 3 to 5 seconds during the initial sounding of the alarm the engine looses some power for a second or two then back to normal power. If I only accelerate to about 3000 RPMs the alarm doesn’t go off. Put it back at idle no alarm go back to full throttle 15 seconds later the alarm goes off sounds until for a couple seconds then goes off. I was thinking it is a overtemperature overheating alarm however the water bypass is warm to the touch but not hot. I can touch the top of the cylinder heads and thermostat area and it is not hot. Doesn’t seem like the engine is overheating. I have tested the throttle position sensor with a volt meter and reads within normal limits. I have checked all of the coil packs with a in-line spark plug tester and all are firing. When I run it on the water hose at home the alarm does not go off. Please Help

 

[TimOare]

Your wear ring is probably worn, too much clearance for your impeller, not enough drag- engine spins impeller too fast- over speed engine.

 

[Aquaman1]

How would I check or measure the wear ring?

 

[TimOare]

You may be able to shove your head enough up once debris grate is removed for a look. There should be pretty much just a 1/32 clearance from the wall to the blade- almost touching.
I removed mine fully and coated it it in JB weld, sanded and then install impeller, checked clearance- repeated until it was practically dragging on sides and an even gap all around. Time consuming but has been that way for 2 years. I couldn’t afford to have mine sleeved in SS. I don’t go near a lot of rocks and regular small debris - it seems to hold up well.

 

[SKutopia]

one beep could be a variety of issues .. see attached guide

 

[Boater775]

one beep could be a variety of issues .. see attached guide

Thanks !!!