great day boating but.....

Strange High pitch whine (sounds like an alarm buzzer just not as constant, still it's very piercing) out of port engine 500 efi (50 hrs). No power loss all fluids ok- runs 110mph easily with no problems. Here's the weird thing.... Goes away in reverse and idle forward. Neutral starts again. bring it up on plane starts again. When I turn the engine off it takes a second and a half to die out. Brand new drives so no issues with equipment. plus it's coming frome somwhere around the engine. It's so high pitch your ears won't let you isolate it.

Any Ideas?

Last week I sucked a little grass up but no big deal. flushed oil coolers with no hiccups.


Thanks for your help.

Maximus

Must be the hidden supercharger.

I wish!
Maxximus

Did ya check for a potato in the tailpipe?

Gimble bearing???

It means it's about to puke and you should trade it even with me for a SBC.

Seriously, my first supect in all high pitch whines is a vacumn leak, but it wouldn't go away by changing gears.

I had a 96 Scarab with t/500 HP's and had a similar high pitch
whine. I do not recall if it was a pulley for the belts out of a line or a bad belt. Look at the belts and alinement or a belt too tight.
One or the other fixed our problem.
Doug

continues for a little after shutoff??

Fuel pressure regulator on the fuel rails???

Does it whine louder with more RPMS?

Mine sounded like I was running a blower engine.

If it has XR Bravo's and not XZ Bravo's it's the drive due to the way the gear is a straight cut in the XR vs. a bevel or angle cut gear in the XZ or Bravo 1.

I remember it in the 38 Cig thought I was going to launch all the engine guts out of the top of the engine hatch.