Ok, am trying to figure out this problem for my buddy. He's got an 02 Baja 29 SST with twing 496s.

There is water coming into the bilge/engine room from somewhere, but ONLY at speed and over 3000 rpm. If we just put it in the water and idle around, its dry. Checked all hoses, sea pumps etc. Tried cruising with the hatch open, but still couldnt locate it. Bellows look fine too.

Any ideas??

Change impellors recently? I've had a cracked housing before, but I could see it leak at idle.

I'll put $20 bucks on the fact that it's one of the 496 air actuators that you use to drain the sea water. The spings in them go bad after a while; somewhat common problem.

There is one on the front and back of each motor. They are rebuildable, but I've opted for new actuator assemblies each time.

If you just put in in neutral and rev up the motor gradually, I bet you will find it. Do it one motor at a time if doing it while the boat is in the water.

Or it could be a problem like mine. I put in a new Livorsi GPS speedo when my speedo stopped working. Unknown to me, it had become disconnected under the motor somewhere. When at speed, it was still pumping water into the bilge through that little damned hose.... Go figure. Lol!

Some good tipss! Will look at the air actuators,

I had the same problem with a cracked housing too, but as mentioned, you still see water leaking at idle.

Speedo hasnt been changed either.

I have had a cracked sea pump body and it only leaked above 3000rpms when the water psi got over about 15psi.