Funny Story (well now I can laugh anyway)

M Prod

Well-Known Member
Oct 6, 2017
1,438
North Vancouver, BC
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!!

image1.jpeg


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. :)
 
look on the brighter side, most owners would have called their mechanic and paid a few hundred bucks for the lesson!
Carpe Diem
 
Heh. Thats a lesson we all have to learn (myself, more than once). My latest hickup was that the port engine wouldn't start. Not even a click. After bypassing the neutral safety switch and tearing apart the helm wiring, I replaced the Slave starter solenoid, because dag-nabbit, everybody says they go bad. Still wouldn't start. Finally, I unplugged the cable that goes to the helm and cleaned the contacts, and damn-bang...there it was.
 
look on the brighter side, most owners would have called their mechanic and paid a few hundred bucks for the lesson!
Carpe Diem

And plus a spare impeller to add to the collection! (spares bag was at home in the garage. Guess it looked like a bag of clothes from the last trip according to a frustrating phone call I made to my wife when I thought I needed an impeller)
 
The raw water pump impellers seems very tough. I ran both engines for 10 minutes when we first got the boat with no water flow. Went over a lager clump of sea weed and algae in a marina. Boat sounded very load but I was not sure why. Generator plugs off from time to time I now know want low and no water flow in exhaust sound like. I carry spare raw pumps one for 454s and one for generator. Thanks for sharing experience we all learn form our mistakes. Are your raw water pumps brass. Ours are hard plastic.
 
The raw water pump impellers seems very tough. I ran both engines for 10 minutes when we first got the boat with no water flow. Went over a lager clump of sea weed and algae in a marina. Boat sounded very load but I was not sure why. Generator plugs off from time to time I now know want low and no water flow in exhaust sound like. I carry spare raw pumps one for 454s and one for generator. Thanks for sharing experience we all learn form our mistakes. Are your raw water pumps brass. Ours are hard plastic.

Mine are brass, yes. Thinking after next season I’ll replace with the stainless aftermarket versions. The brass ones I replace every 2 years ...stainless would basically last forever.
 
Kind of reminds me of a dock neighbor, super nice guy. His starboard wouldn't start, not even click. He found this during the week and call a mechanic to come look at it but couldn't get an appointment till the next week. During the weekend he was telling another neighbor which said pop the hatch and let's take a look. When I arrived at the marina and was taking stuff to my boat, I walk by and say, what's up Steve that don't look good. He said it's not, starboard won't do anything. Robin is in the engine room now taking a look because I can't get a mechanic here till next week. I jokingly said well take it out of gear. The look on his face when he put the shifter in neutral was priceless. Goes back to that expecting the worst thingy.... We've all been there but we still tease him. :D
 
Hauled out last week for winter storage. Did the necessary muffler water drainage and shut the strainer valves. Opened the starboard strainer and fired up the engine and poured AF into the strainer and watched as AF came out the exhaust. Tried the same on the port side and pouring AF in the strainer did not work. AF just overflowed into the bilge. Immediately figured the impeller was shot. Valuing my body and skin, I called in my mechanic. He removed the intake hose and filled a bucket with antifreeze, put the hose in the bucket and fired up the engine. Watched the AF spew out of the exhaust to my delight. Anybody ever have an AIR LOCK like that? The water pump and impeller were fine. The blockage air lock occurred due to the haul out. Maybe close the strainers prior to haul out is in order. Lesson learned.
 
Kind of reminds me of a dock neighbor, super nice guy. His starboard wouldn't start, not even click. He found this during the week and call a mechanic to come look at it but couldn't get an appointment till the next week. During the weekend he was telling another neighbor which said pop the hatch and let's take a look. When I arrived at the marina and was taking stuff to my boat, I walk by and say, what's up Steve that don't look good. He said it's not, starboard won't do anything. Robin is in the engine room now taking a look because I can't get a mechanic here till next week. I jokingly said well take it out of gear. The look on his face when he put the shifter in neutral was priceless. Goes back to that expecting the worst thingy.... We've all been there but we still tease him. :D
I did this, but twice in within about 30 minutes. Started engines, all good. Shut them down for some reason. Tried starting generator, wouldn’t start. Called generator repair on a Saturday, they had just serviced it, no luck, left a message. Finally checked and opened the bilge, sure enough, the switch was in the off position. Put to auto, gen fired right up. Tech called, had to sheepishly explain what happened. THEN my port engine wouldn’t crank at all. I was dumbfounded, IT JUST STARTED UP NO PROBLEM!! After 10 minutes, realized I had ever so slightly bumped the shifter about 2 mm while going back and forth trying to get the gen to start!
 
A few years ago I did a similar thing anchored out with the trani in gear... Ripped that boat apart trying to figure out why it wouldn't start.... When my wife finely asked what I was doing and I told her ....she said is the gear shift in neutral?
 
Kind of reminds me of a dock neighbor, super nice guy. His starboard wouldn't start, not even click. He found this during the week and call a mechanic to come look at it but couldn't get an appointment till the next week. During the weekend he was telling another neighbor which said pop the hatch and let's take a look. When I arrived at the marina and was taking stuff to my boat, I walk by and say, what's up Steve that don't look good. He said it's not, starboard won't do anything. Robin is in the engine room now taking a look because I can't get a mechanic here till next week. I jokingly said well take it out of gear. The look on his face when he put the shifter in neutral was priceless. Goes back to that expecting the worst thingy.... We've all been there but we still tease him. :D
This is more common than one would think. It happened a few years ago at the end of a fun weekend. Were wrapping up, loading the boat and ready to shove off. To the helm try to fire the engines.....Starboard won't start, crap! I recently replaced the starter relay on the port engine, and my mind went immediately thinking the other side is now bad. Climbing around, trying to "jump" the engine, only to find I don't have power......back to the helm, jiggle the shift in and out of gear.....engine fires. Hahah, never underestimate the simple tests first.
 
I ve definitely had more than a few brief moments of panic with engines not starting, only to realize I’m slightly out of neutral for whatever reason.
 
The plastic raw water pumps do not seem to wear. The one that just failed on us (Bearing) the housing is fine. probably 1500 hours on it. The SS wear plate gets some groves in it but not the plastic.
 
Don't feel bad. I did it this week. Genny wouldn't start. On my 320 there wasn't a pre-heat period. On the 500 there is. I wasn't holding button on long enough to pre-heat...Learning new systems are fun...We spent about an hour swapping batteries, jumper cables etc before I gave up. Tech started it this week with ease.
 
Hauled out last week for winter storage. Did the necessary muffler water drainage and shut the strainer valves. Opened the starboard strainer and fired up the engine and poured AF into the strainer and watched as AF came out the exhaust. Tried the same on the port side and pouring AF in the strainer did not work. AF just overflowed into the bilge. Immediately figured the impeller was shot. Valuing my body and skin, I called in my mechanic. He removed the intake hose and filled a bucket with antifreeze, put the hose in the bucket and fired up the engine. Watched the AF spew out of the exhaust to my delight. Anybody ever have an AIR LOCK like that? The water pump and impeller were fine. The blockage air lock occurred due to the haul out. Maybe close the strainers prior to haul out is in order. Lesson learned.

Yup that's happened to me. Again thought my impeller was shot the first time. If you just rev the engine a bit the pump should prime and suction will be restored.
 

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