Suzuki DF50 outboard water pump issue...

[Jeepster]

Hi, I have a 2000 vintage fuel injected Suzuki DF50. The engine has done very low hours for its age and the cosmetic condition reflects this, but whilst it looks good and runs lovely, I can't seem to get the water pump on top of the gearbox to work properly even after fitting a new impeller, which has rendered the engine useless. The tell-tail either never works, or just has a very weak intermittent dribble and instead of water I start getting steam out of it after warming the engine up for a few minutes!
Question...Is it normal to have water jetting quite strongly out of the two little openings on the front of the leg at the joint between the gearbox and the leg, and flowing out from where the gear selector rod exits the gearbox, whilst the engine is running? I run the engine in a plastic water tank, so there is plenty of water feeding the pump.
I am guessing this is a clear sign the vertical water pipe inside the bottom of the leg isn't mating with the rubber grommet in the top of the impellor housing properly allowing pumped water to flow inside the leg on top of the gearbox???
Can anyone suggest a simple cure, for example, fit a new Grommet? (even though there doesn't appear to be anything wrong with the old one), extend the pipe? Bodge it?
Thanks in advance.
Alf.

 

[jamie langstone]

If i remember the tell tail is plastic (where the water should come out) if it is the same as the one i have on a similar engine. The plastic tell tail gets encrusted with salt and then blocks so either disconnect from rubber pipe and cowling and place in boiling hot water to dissolve the salt or try clear it with a small peace of wire to clear the channel . Either method used to work for me

 

[VicS]

Hi, I have a 2000 vintage fuel injected Suzuki DF50. The engine has done very low hours for its age and the cosmetic condition reflects this, but whilst it looks good and runs lovely, I can't seem to get the water pump on top of the gearbox to work properly even after fitting a new impeller, which has rendered the engine useless. The tell-tail either never works, or just has a very weak intermittent dribble and instead of water I start getting steam out of it after warming the engine up for a few minutes!

The telltale may be blocked .. try cleaning as suggested. It is only a telltale to indicate that water is being pumped to the power head but steam issuing from anywhere is a bad sign. it means that the engine must be overheating due to lack of cooling water flow

Question...Is it normal to have water jetting quite strongly out of the two little openings on the front of the leg at the joint between the gearbox and the leg, and flowing out from where the gear selector rod exits the gearbox, whilst the engine is running? I run the engine in a plastic water tank, so there is plenty of water feeding the pump.

Water will normally exit from those openings but normally they will be immersed so you will not see it.

You do not appear to have the engine immersed deeply enough. Immerse it to a point where that joint and the water pump itself are below the water level.

I am guessing this is a clear sign the vertical water pipe inside the bottom of the leg isn't mating with the rubber grommet in the top of the impellor housing properly allowing pumped water to flow inside the leg on top of the gearbox???
Can anyone suggest a simple cure, for example, fit a new Grommet? (even though there doesn't appear to be anything wrong with the old one), extend the pipe? Bodge it?
Thanks in advance.

It does seem though that even at that depth the pump is pumping well. Are you sure the water tube has entered the grommet properly. Are you sure the grommet is in good condition
Could it be that the water tube is damaged or blocked. Is the top grommet OK?

Try connecting a hose to the water tube to check that water will then then issue from the telltale and pass through the engine. You may have to remove the thermostat to be sure.

 

[MikeFloutier]

I have a 2008 DF50 which is similar and had the same symptoms the OP described and thought that sharing my journey might be helpful to others. Occasionally the pilot hole flow would stop completely.

1. Since the pilot hole exit is the smallest aperture in the entire system it's a likely culprit so, as has been said, remove and clean this first and run the engine to flush any local debris before re-fitting. All may now be well.

2. Check water inlet filter/mesh, in the lower leg for blockages and clean.

3. A slight aside; if you're getting a flow at the pilot hole but still getting overheating then there is a blockage preventing water from reaching the head. This may be a failed thermostat or a blockage in the head's channels.

Check the thermostat by immersing in hot water, it should open at a certain temp, e.g. 70deg (see manual). If it doesn't open replace the stat; cheap and easy.

To check for flow through the head, remove the stat then remove the lower end of the large return pipe (one that comes out of the stat) and try to blow air through the head. If it's clear you'll hear it and feel it. If not...

3. There are several pretty small bore rubber pipes around the pilot hole area. Due to their size they are also possibilities for blockage although mine were all fine. Simply remove these and blow though to check and also poke through with heavy duty strimmer line (care not to damage rubber).

4. My DF50 (looking at the stat and on down into the head) appeared to be suffering from severe encrustations.

I decided to flush the system with neat distilled vinegar which I ended up buying from Aldi at 25p per pint; by far the best price I could find.

I removed the stat (to ensure the head got flushed) and circulated the vinegar through, using a dustbin for the leg (ensuring that the level was sufficient to prime the impeller unit).

I ran it like this for an hour or so at around 1700 revs. The temp in the bin quickly rose, which was good as I didn't want to be running the engine cold for long, bearing in mind the stat was missing.

After an hour I stopped and siphoned the vinegar into a couple of 5 gallon drums ready for next time. I was careful not to disturb the sediment and after all the vinegar was gone I had about two teaspoonfuls of gritty, sandy, gungy muck left in the bottom, plus some that was sticking to the leg itself.

I then flushed with fresh water as I didn't know what effect the vinegar would have longer term.

I then repeated the process after the vinegar had cooled, a few days later and was rewarded with another couple of teaspoons of gunk. Flushed with this success, I've carried on about twice a week and have now completed at least 7 flushings over a month or so (nice to keep the motor running over the winter anyway).

I'm still getting quite a bit of gunk each time but the quantity is starting to fall off. In a week or so I'll install the new stat plus fresh spark plugs and should be good to go.

5. Other items I checked were the impeller installation and that the water pipe was fitting snugly in the grommet on top of the water pump housing.

6. btw, water coming out of the holes in front of the leg and the gear linkage hole seem normal. Provides drainage and prevents unwanted pressure buildup. The fact that they are there implies they are planned for water egress.

 

[TheOrs]

...Loads of interesting and helpful stuff...

Thanks! Very interesting.