225 HPDI Water Presure

I always have run 28psi water presure WOT.I have been running in river water,little muddy but not real bad,and I ALWAYS back flush engine after I get home if river is up and nasty.Now I only can get 12 to 14psi.Engine still runs good and not getting hot but pee stream don't seem as strong either.What is clogged up and how do I clean it?Also,water pump only has 45 hours on it. Thanks in advance.

Forgot to tell you. Its a 09 model HPDI Series II

Nobody knows?I guess I'll have to take off work,drive over 100 miles to shop, and leave it there for a month because they are behind.It's probably something simple I can do at home but I don't want to tare into it if I don't have to.I was just hoping for some advise.

Your water pressure, at 28 psi sounds extremely high.

I don't have the specs for the pressure control valve on your model year (or earlier ones for that matter), but at least on Merc's (Opti's) they are fully open at about 10 psi.

So on an Opti, I would consider 12-14 psi to be "excellent". If the HPDI's are similar I would suspect you might have had a sticky pressure valve that is now functioning properly.

But as noted over on the Merc board, try and get ahold of Just-In-Time. He should be able to give you the normal specs for the water pressure...

Thanks for your time