Oh no!, no water going into the engine...

[Juan]

Last winter (like any winter in the past 5 years) I winterized my boat. For the engine this means getting rid of the water inside the engine and putting anti-freeze instead. Yesterday, I forgot to open the valve that let water come into the engine, and so I turned the engine on. The engine started without problem. It was working for about 20 minutes before I noticed white smoke coming out of the exhaust. Of course no water was coming out. At that moment I opened the valve and 1 minute later, the smoke was gone and water started to come out of the exhaust as normal.

I ran the engine for one additional hour and move the boat from place to place, and everything seems to be fine. No problem with the engine, good acceleration, etc. I wonder, however, if the fact that the engine was working for about  20 minutes without water may have done something to it that I might see more in the long run. Should I be concern or these engines are so tough that they can handle this kind of stress..

[Footloose]

The biggest factor is did the engine overheat?  If it did not, the engine should be fine.  20 minutes was probally not long enough to overheat the engine even with the through hull closed.  It takes almost that long to get up to normal operating temperature.  I would replace the impeller as they don't like to go for long periods without water for lubrication.

[Clay Greene]

I agree about replacing the impeller and consider using a Globe impeller, which provides better protection in case this happens again.

[Jim Hardesty]

I agree including the impeller change.  FWIW I use a winterizing and dewinterizing check list.  Also tape the key to the seacock handle after winterizing the engine.  If I take the key off, I put a big label on the key reminding me to turn the seacock on.  I don't trust my memory, it's tricked me before.
Jim

[Clay Greene]

We use a checklist as well.  We also take out the impeller over the winter, and unscrew the water intake filter and cover and leave them on top of the head counter.  We could certainly still make the same mistake but hopefully we have enough reminders so that this is one thing we don't miss. 

We also installed an overheat alarm buzzer to the engine panel last summer - our 1989 was installed without one.  That gives us a little more peace of mind in case we are not getting water throughput and I forget to check before we leave the dock.  That last part is of course the best protection but I can't say I am perfect in checking each time. 

[Jim Hardesty]

I also installed an alarm
http://www.borelmfg.com/products_alarm.htm
When I did it they offered the alarm with low fuel vacuum pressure (dirty filter) and exhust over temperature, probably still do.  Didn't see it on their site.
Jim

[Clay Greene]

Wow - that's really interesting.  The sensor is a band on the exhaust hose rather than a temperature sender mounted on the engine.  That really makes a lot of sense.  Where did you mount the panel?  Did you run power from the engine panel? 

[Clay Greene]

And did you mount the sensor on the exhaust riser?  Looking through the instructions quickly, that seems to be where they suggest. 

[Ron Hill]

Juan : It sounds as though you left your boat in the water over the winter!! 
There are different procedures for storage on the hard and in the water, so make yourself a check list for the splash and/or engine restart in the spring.

Beside the impeller change you need to watch the fiberglass inlet pipe on your muffler.  The muffler doesn't hold up well with out the raw water cooling mixing with the exhaust gases going into that muffler.

20 minutes is a long time without any water, even at an idle.

A few thoughts

[tonywright]

I always close the thru-hull when leaving the boat.  My thinking is that if all the thru-hulls are closed, the bilge pump won't have to work too hard.

To remind me to open it before starting the engine, I leave the engine keys looped over the thru-hull valve! Makes it much harder to forget. It was a great idea I got from the PO.

Tony

[scotty]

I do the same as Tony.

[Juan]

Thanks a lot guys!

Any tips on how to change the water pump impeller? I couldn't find instructions in this website.

Best,

Juan

[Clay Greene]

I can only speak to the Oberdoerfer, which has four screws on the front.  You'll need the new impeller (as I mentioned above, I recommend the blue Globe impellers), the paper gasket (which needs to be replaced when you take off the cover) and some petroleum jelly. 

If you are in the water, close the water intake valve.  Get a bucket to put under the water pump, as water will come out when you take off the cover.  Unscrew the four screws.  There is a metal retaining ring on the inside of the impeller that holds the impeller on the pump shaft.  You will need to pry this off with a small screwdriver - be careful, as it will go flying when it comes loose.  Press the pump shaft toward the engine as you pull the old impeller off; otherwise, the pump shaft can pull out of the engine body.  Once you have the impeller off, count the vanes to make sure that none have broken off.  If they have, you are going to have to locate them in the elbow of the water pump, the hose that leads to the heat exchanger or the heat exchanger itself.  Lightly coat the impeller in petroleum jelly - this will protect it when the pump starts turning before water is drawn to the pump.  Slide the new impeller onto the pump shaft - you will need to compress a couple of the vanes to make it fit.  Replace the retaining ring, making sure to get it seated in the groove.  There are two flat ends of the ring - these go on the flat section of the pump shaft.  You likely will have seen this when you took the retaining ring off.  A second small screwdriver is helpful for holding the ring in place on one side while you press it in on the other.  Replace the paper gasket on the inside of the cover and screw the cover back in place.  Open up the raw water intake.  Start the engine and make sure you have water coming out the exhaust port.  Others will mention if I have missed something. 

I noticed that my boat (#873) was next off the production line after yours in 1988.  It would be interesting to compare notes on our "sister" vessels. 

[TonyP]

Juan

It should be just a matter of unscrewing the face plate screws, (ours ( Johnson) has 6 but yours may differ depending on pump brand) and prizing the face plate off. Our impeller then just pulls straight out. Clean the old gasket from the plate and pump housing, lube and fit impeller, replace gasket and screw plate back on.
Ours has a centre pin pre fitted to the impeller that fits in an end slot in the shaft. Others may have a keyway which could be more difficult to remove.
good luck
Tony

PS ... Clay ... you got me whilst typing

[Clay Greene]

I will mention on the impeller vane issue that we had an overheating issue when we bought the boat - we always ran at about 180-185 degrees.  We pulled off the hose from the water pump to the heat exchange and found an impeller vane in the elbow of the water pump.  We put the hose back on and tried it again.  Still overheating.  We took the hose off at the heat exchanger end and found another vane at the HE end of the hose.  We put the hose back on a second time and started the engine.  Still overheating.  We then took off the heat exchanger and disassembled it.  We found three more impeller vanes in the HE.  We cleaned the HE and reinstalled it.  We started the engine and she has been running beautifully at 160 blissful degrees for the last five years.  PO must have thought that hard rubber impeller vanes evaporate in the HE or he didn't mind that the engine was running 20 degrees too hot.