Suzuki DF 50

[Hydrotherapy]

Are there any mechanics out there? I have a 2003 Suzuki DF 50 on my 26x. I guess it must have been a year since I had started it. Finally it rose to the top of my to do list. When I tried to start it, it cranked over but would not fire up. It has spark, but no fuel. I have flow from the low pressure pump, but not from the high pressure pump. The fuel smells like varnish. I am wondering if there is a way of confirming a bad fuel pump, or if some sort of flush could revive it.
Any advice would be appreciated. I really hate myself right now!
thanks,
Kevin

[kleinhhl]

I had the exact same symptoms on my 2000 Suzuki DF-50 engine. After a long period of sitting, the gas had turned bad and the engine would not run. After making sure I had spark and fuel flow through the low pressure fuel pump, I focused on the high pressure pump. Long story short, the high pressure fuel pump needed to be replaced.

The repair is easy if you have the Suzuki service manual and the right tools (nothing special). I bought all of my parts from Browns Point Marina. Here is a link to your engine's model year parts diagrams: http://store.brownspoint.com/df50/05001F.asp

I believe Figure 12 is what you need to look at. Part no 15200-87J10 seems to be the high pressure fuel pump. I'm not aware of any test procedure to see if your current high pressure pump is not working short of possibly an engine code being thrown... but then you'd need a ECM debug device that you could hook up to the engine's computer.

Replacing the pump solved my problem. The engine started right up and went back to its old reliable self.

Lesson learning... don't leave gas in the engine for long periods of time.

-Hugo
No longer own my MacGregor 26X

[Hydrotherapy]

Hugo,
Thanks, I guess I have my work cut out for me.
Kevin

[Catigale]

Im guessing the HP fuel pump has a simple two wire connection for pos and neg 12 VDC. Could you just briefly apply 12 V to the terminals (correct polarity) and see if it hums at least as a simple check?

[Carl Noble]

When I had my X I always added Sta-bil to the gas tanks. Some years I would go thru 30 gals. of gas and other years only 4 gal. The gas was good for the entire season (6 months) and any left overs were put in my vehicles at the end of the season. I always kept at least 2 6gal. tanks onboard. Also at the end of the season I would be sure to empty the gas from the engine by letting it run dry before putting it on the trailer.

[kleinhhl]

Doing what Catigale suggests might be a good test to perform prior to ripping apart your engine. The parts diagram shows the high pressure fuel pump as part of the fuel vapor separator and there is a power/control connector but I can't remember if it's easily accessible or how many wires go to it. You could try applying +12V/GND to the pump to see if it operates. It should be a high pitched wine as long as there's fuel in the fuel vapor separator.

I also remembered checking the fuel injectors to make sure they weren't clogged. I think there's a procedure in the service manual. Here is a list of parts that I purchased when I did this job: http://www.cooperchemical.com/bajariha/DF-50-Parts.pdf. I know it's long but I did some other maintenance/repairs as well since my engine sat for a while.

1. Replaced high pressure fuel pump and associated system.
2. Replaced high pressure fuel filter and low pressure fuel filter.
3. Changed all fluids: i.e., oil, lower unit oil, hydraulic lift oil
4. Replaced water impeller
5. Check air filter

I'm not sure of your skill level but I was able to do all of this work my self without worrying about screwing up the engine. I'm not a mechanic or anything like that. Hope this helps,

Hugo
Mac-less now that I sold my 26X

[bahama bound]

so what performce would i have with a 50 four stroke with my x ?im just trying to find the balance of both worlds ???? cruise speed with 50 four stroke ???

[Hydrotherapy]

Thanks for all of the ideas. I ran voltage to the pump motor connector, and the pump does not start. I suspect the pump is stuck or dead. One other thing I tried was to test for voltage coming into the pump. To do this I turned the ignition key on, and found no voltage during that test. I also tested the input plug during cranking, and found no voltage. I wonder, is this test an indication of an additional problem, or am I testing the supply voltage incorrectly?
I checked the print in the service manual, it shows a wire to the pump motor coming out of the engine control module. I think the other wire is probably the ground. I was hoping to find a fuse or breaker tripped or something along those lines. No luck yet. Any theories as to whether I should have power at the supply plug either when the key is on or during cranking?

[Catigale]

Hmmm. That's disturbing. I can't imagine why don't get 12 VDC to the pump with key on.

Sounds like. Someone on the board with a Suzuki needs to run the test on a working motor....

[Don T]

Hello,
Seems to me the HP pump should only run when the motor is running or when cranking the starter (and 5 seconds after). It should be fused. Generally speaking, these systems usually control the ground side of the circuit. If you clip your tester to a power source and test the pump connector you may find the controller is providing the ground while cranking.

[Catigale]

Don..I would think the high pressure pump would bring the EFI up to working pressure before engine start. Pretty sure this is how my Merc BF 50 works.

[kleinhhl]

I've done some cursory searches on Google for the same problem you're facing and it seems like other DF-50 owners have similar problems with their engines. Based on my experience where the high pressure fuel pump did stop working on me after sitting for about one year, I'd say that is your problem. Others have said that any fuel with ethanol content above E-10 can cause fuel clogs throughout the fuel system in the Suzuki DF-50. I would definitely recommend using SeaFoam on a periodic basis.

That being said, I'd check the fuel system from the low pressure side all the way through to the fuel injectors. Change the filters, inspect the fuel injectors and look for any signs of debris or congealed gasoline in the system.

As far as checking for voltage/currents in the system, I'm not sure what type of signal the ECM uses to control the fuel pump. It may be a simple binary +12V on and 0V off or it could be a more complex digital signal like Pulse Width Modulation where the ECM rapidly turns the pump on/off. If this is the case, it may explain why your DVM didn't show a reading. On the connector side, it may be that you need to present a load (i.e., impedance) for any current to flow. Without a load, you won't read a voltage.

I'd like to give you a more concrete answer but my gut feeling says it needs a new high pressure fuel pump and a thorough inspection of the fuel system.

Regards,

Hugo

[Hydrotherapy]

Once again, I am impressed at the amount of support at this site. I am going to replace the HP Fuel pump. I will update as I progress. I think I have learned as I hope others have, that a little bit of Stabil added to the fuel is not a bad thing.
Thanks again,
Hydrotherapy Out

[Catigale]

from the IBOAT forum (un-referenced, UAOR)

The sensor tell the computer the engine is running, when the engine stops the fuel pump stops, except when turning the key on. Then the pump only runs for a few seconds to charge the system with fuel.

This makes sense to me,a nd is exactly what my Merc does.

If the ECM doesn't detect the engine running, it shuts off the high pressure pump. Im guessing you turned your key on, then went back and looked for 12VDC at the high pressure pump contacts? By the time you got back there, it was gone...

Maybe try hooking up the DVM to the contacts so you can see the DVM, then turn they key on and see if it goes to 12 VDC?? Ill give the Bills 5 points that it does...and thus your high pressure pump being dead is the correct diagnosis.

[tegwilym]

I'm having a similar problem, but suspecting I have a dead HP pump. How loud is the high pitched whine sound when it comes on? I'm not hearing anything on my DF50. I did check voltage and it is showing a good solid 12V for the 3 seconds when you turn the switch on, so that is ok and it should be getting power. I do hear a faint click of the relay, but not much else.

Tom