The whole system is raw water. I considered there might be an air leak so I'm replacing the cork seals in the sea strainer and have checked all the clamps for tightness.

That's worth checking. I know how to do timing but have never done it on a boat. What is the procedure and setting?

Thanks,

Steve, How long have you owned this boat? Did it just start happening or was it after a repair?

This is my 3rd season with the boat. The problem just showed up one day. We like to anchor in shallow water with a sandy bottom and I have found some sand in the strainer and lines so I think maybe that is the cause.

The problem is I can't seem to solve the problem. This time I tore it down and flushed even more sand out. Right now, everything runs clear when I backflush. Before I put everthing back on, are there any other tests or procedures I should do?

Right now, given all the sand I got out, I'm cautiously optimistic.

Thanks,

It's extremely rare but sometimes the hose from your intake up to the strainer/water pump can collapse even though it's a wire bound hose. As the hose gets old the inside of the hose seperates from the outside and the more throttle you give it the more the hose collapses....

It's an outside shot but if nothing else just replace the hose to be sure.

Good tip. Thank you.

Did you look through the oil cooler?. I have backflushed and things looked normal but there where impeller parts, sand, lodged into the tubes the water passes though.

They would not come through backflushing them.

Did you find the missing vein from when you replaced the impeller?????

If yes, replace the entire housing for the sea pump if its one of the plastic ones.

ONLY USE MERC IMPELLERS/HOUSINGS!!!!!! The Sierra stuff is junk.

I did not look through it. It is nearly impossible to even reach. I'm not sure I could get it out without either pulling the engine or removing the exhaust manifold.

In your case, how did you get the crud out? Do you think I could back flush with more pressure some how to dislodge any stubborn stuff?

I found a bunch of impeller parts when I back flushed. I did not try to determine if I had accounted for all the pieces though in hind site, I should have.

I bought a Sierra but after reading some threads here I bought a genuine Mercruiser kit and that is what's going back in.

What are the possible materials my housing would be made of? Mine might be plastic. It is light and does not sound metallic when tapped.