Should it be this loud at idle with water going thru the pump?   

wow that does not sound good. I hope you did not run it long like that. You need to pull it apart and find out what is going on..

i would say it is more likely your u joint then. Not your pump. Pull your ujoint off and check to see if it is still good. there should be no play in it. if there is that is your problem not your pump.

I would almost put 5$ on it now that i think about it

if it was a pump clearance issue it would get worse ifyou went faster. Since the u joint is under a load at speed it stops making noise. but at idle it has time to rattle.

so since the Ujoints have play in them its causing the pump shaft to move causing the imp to make noise?  When i am in the boat it does sound like stainless steel rattling.  Hard to hear in movie.

The U-Joints will not allow the pump shaft to move, good, bad, indifferent. However, and I agree with Tony's speculation that the U-joints may be the bulk of the noise, it would also indicate to me that it's bearing time in the pump. If the U-joints were ill-maintained or just tired enough to reach that condition, time to look into the pump anyway, as it's probably in a similar state. The bad u-joints could also be the cause of the input bearing to fail, if it has.

News is, you gotta remove the engine, or the pump, to get the 1310 d/l out to replace the u-joints anyway, so might as well be the pump and go through it. 

Ray

Anybody know what a rough estimate is for a rebuild at a shop?  Can it be done in a driveway with common tools?

Took it over to MPD in costa mesa.  Nice guy and really seems to know his stuff.  He said a majority of the noise was the ujoints.  Imp had some knicks but not bad.  wear ring looked to be in good condition (no burrs like it would have if the imp was hitting it).  guess i will run it all summer then next winter have him blueprint it.