M Prod
Well-Known Member
- Oct 6, 2017
- 1,438
- Boat Info
- 2005 Sundancer 340
Zodiac Cadet w/FCT console Yamaha F20
Kohler 5KW Genny
- Engines
- 8.1 Horizons /V Drives
So today I was down at my boat doing some prep for a getaway we're planning for this weekend. I was going to take it around the corner to the gas dock and stop at the pump out to flush the holding tank. I started up the engines ...first starboard, then port. I did not go out to check the raw water discharge as I usually do (don't know why ..my mind was elsewhere). I was more focused on what the batteries were doing seeing as I had a new alternator on port, and starboard wasn't quite as high a charge. I decided to rev starboard slightly and immediately got a water pressure alarm. I looked down at the smart craft and sure enough ...0 psi on starboard. I immediately shut the engine off and then I remembered. CRAP! I had closed the seacock the previous night as I had cleaned the strainer and never opened it back up. The engine had run dry for at least a minute. Anyway praying now, I opened the seacock and fired up the engine again. Pressure went up just a bit but then returned to zero. I revved the engine a tad to see if the pump would prime, but to no avail. Damn. It. Fearing the worst, I went to the parts store and picked up an impeller and returned to the boat to begin the arduous task of changing it out. Now I know not all of you know the joys of changing an impeller on an 8.1 in a 340, but it's ...challenging to say the least. But it needed to be done, so I rolled up my sleeves and began the gruelling task of removing the exhaust hose, removing the serpentine belt, removing the pulleys that the pump bracket fastens to, another trip to the store to get a socket I needed, removed all the bolts holding the pump, removed the hoses, pulled the pump, and finally took it apart on the dock after removing the 6 bolts that hold it together (mind you doing this all in the most awkward contorted and hunched positions ..my back is screaming at me tonight). Upon opening the pump fully expecting to find a shredded impeller, guess what I found??????
THIS!!
I felt two emotions at this time ..confusion as to what the heck was going on, and relief that impeller parts weren't buried downstream in my cooling system. So what happened? I started looking and thinking and looking and thinking ..and then there. There it was staring me in the face. Right there ..right next to the dang seacock through hull I had opened in the first place. The valve that goes to my fresh water flush hose hook up. It's right there next to the strainer and when I leaned over the strainer to open the seacock, my chest must have pushed it just enough (we're talking 1/4 of the way) open to prevent a vacuum from forming in the raw water intake. That's why there was no pressure. And so I began the slow and painful task of re-installing the water pump, getting plenty of bumps bruises and even a cut or two along the way. Fired up the engine, and sure enough ..all systems normal.
Long story short (and I know this but just saying it again because I obviously need to hear it again) always start with the simplest potential problem and work your way up to the more serious. I immediately assumed the worst and so I spent 3+ hours contorting with my water pump instead of finding what should have been a very easily solved problem. Oh well ..I suppose next time I need to replace a water pump/change an impeller it'll only take me 2 hours.
THIS!!
I felt two emotions at this time ..confusion as to what the heck was going on, and relief that impeller parts weren't buried downstream in my cooling system. So what happened? I started looking and thinking and looking and thinking ..and then there. There it was staring me in the face. Right there ..right next to the dang seacock through hull I had opened in the first place. The valve that goes to my fresh water flush hose hook up. It's right there next to the strainer and when I leaned over the strainer to open the seacock, my chest must have pushed it just enough (we're talking 1/4 of the way) open to prevent a vacuum from forming in the raw water intake. That's why there was no pressure. And so I began the slow and painful task of re-installing the water pump, getting plenty of bumps bruises and even a cut or two along the way. Fired up the engine, and sure enough ..all systems normal.
Long story short (and I know this but just saying it again because I obviously need to hear it again) always start with the simplest potential problem and work your way up to the more serious. I immediately assumed the worst and so I spent 3+ hours contorting with my water pump instead of finding what should have been a very easily solved problem. Oh well ..I suppose next time I need to replace a water pump/change an impeller it'll only take me 2 hours.