2006 DF225 problem

[Travelingbass]

I have had this motor for about 3 years now and it has given me almost constant problems. The latest issue is dropping power and stalling completely while running. The engine will suddenly and randomly lose power while running and then not start again for the rest of the day. All evidence I have found so far points to a fuel problem.

When this happens, the bulb will have zero pressure in it and will have to be pumped almost constantly for the engine to start and run again. If I manage to get on plane I can keep it going by sawing back and forth on the throttle each time it starts to die, it will "catch" and get power back again for a few minutes before happening again.

I encountered this same problem a year ago - I replaced the fuel line from the tank to the engine, replaced the bulb, in-line filter, as well as the 2 engine mounted fuel filters. I then ran it and checked for any blockages by blowing air through the fuel line back to the tank and found no issues. It seemed to have fixed the problem for a little while as this is the first time it has done it since last summer. However now I am at a loss and am considering filling it full of bullet holes before setting it on fire.

Any help is greatly appreciated

[billnorman1]

Houston, you have a problem. It sounds like a boat problem to me. If you have an auxilary fuel tank and a place to put it on your boat, and if the problem happens all the time, you could run your motor off of it and be sure your motor is not the issue.
What bothers me is you blew back through the lines and it improved for a while, You may have trash in your tank or a clogged vent hose or fuel lines collapsing because they are not ethanol resistant.
I'd say inspect the fuel lines see if they're USCG approved for ethanol, check the vent hose for obstructions, and if necessary remove the fuel sending unit to inspect the tank with a proctoscope ( which I have ) or a borescope or the naked eye.
If you have 2 tanks the switch may be defective or maladjusted.

[Moonlighter]

I would suggest a couple of things.

First and top of the list is to check fuel pressure, with a gauge. There could be an issue with the LP or HP fuel pumps. If you cant do it, get it done.

Second and this might sound strange, is electrical. These engines dont like poor power supply, and will do strange things when the ecu does not receive a solid, consistent power supply.

So load test the batteries, check the main battery cable connections by undoing them, wire brush, reconnect and tighten. Check the cables for internal corrosion, I find that if you give them a flex around and they feel soft and flexible they are usually OK, but any stiffness or crunchyness they are corroded.

Find the white wire connection to the start battery or main switch, and do the same, take it off, clean it, check the connector is good, looks for signs of corrosion in the connector and adjacent wire.

[Travelingbass]

Update - I checked all electrical connections again and no issue there, the cranking battery is always fully charged and less than 3 months old as well. I was able to check the fuel pressure with a gauge and after about 15 minutes of running it lost pressure and began to stall. I removed about 2 excess of feet of fuel line that was kinked and got rid of the anti-syphon valve on the tank. This helped but did not solve the problem.

Here's what it is doing now after the latest test run; Once the engine is hot and running at WOT, it will lose fuel pressure and rpm's will drop, if I saw the throttle back and forth, it will pick up fuel pressure again, just like before. However, unlike before, it won't stall and then proceed to not start again the rest of the day - if I run it about half throttle I will not experience any issues. But, the second I give it more gas, it loses pressure again, then I back it off to half and it's fine.

My question now is, what are the chances of this being a vapor lock/VST problem? I've read horror stories of others with the this same engine developing a vapor lock problem with no clear solution ever being found

[booter]

It could be getting vapor locked since there is a fuel line cooler on the back side of the VST up near the block. CAPT Dave on Youtube talks about it and goes through a lot of Suzuki maintenance tips as well.

[jbeaudry05]

Sounds like a fuel delivery problem potentially. I would check/replace fuel lines and bulb. And as already stated check the tank for debris

[Travelingbass]

Booter - I really appreciate that link, that's the kind of information I'm looking for

jbeaudry05 - The fuel lines from the tank to the bulb have all been replaced, the bulb was replaced as well. It's just a cheap quicksilver bulb, but it's only a year old, I would imagine even a cheap one should last longer than that. I have limited access to the tank itself, but I shone a light down through the pick-up and couldn't see any obvious debris in the tank. I have not inspected the pick-up itself yet, however.

EDIT: I have also replaced both thermostats, as well as the LP and HP fuel filters as of February of this year

[billnorman1]

Get a portable tank. IF it runs right it's boat. That's easy for me to say but probably harder to rig up. If it does it all the time it would be easier to troubleshoot. If the motor responds to pumping the fuel bulb it's probably a fuel issue, but electronics can be intermittent and heat related. Don't you have a small fuel filter on the motor? Does your fuel pump assembly have a drain screw at the bottom of it to drain contaminants and water?

[Travelingbass]

billnorman1 - I know I should rig up an external tank, but I've been cheap and I'm trying to avoid buying one. There are 2 engine mounted filters and I replaced both of them last year. I'm not sure if there is a drain on either of the pump assemblies or not, but I will look this evening when it dips below 90 degrees.

Here's another update after another day of testing; I went to the lake this morning and as usual, the initial start up and run were fine. I made a 10 minute run at about 80% throttle and set it to down to fish for a while. After about 2.5 hours, I went out to the main lake to try and re-create the problem; I also removed the bilge panel so I could watch the bulb and the clear in-line filter while running. Sure enough, after about 10 minutes of WOT running, it began to lose fuel pressure. It did not stall completely, just lost power momentarily, as I looked back the bulb was completely collapsed. I turned it off, pumped the bulb, and took the fuel filler cap off, ran it again and it only took about 45 seconds to happen again. Since it still did it with the filler cap off, I guessed it wasn't a venting problem, so I switched my focus to the in-line filter. I disconnected the line and drained the filter, upon inspection I could see traces of debris at the bottom, I then tried to blow air through it and only a small amount of air was able to come out the other side. After this, I left the filter off, reconnected the line and ran it for a full 15 minutes at WOT with no issue at all.

However, when I cranked it up to run back to the ramp, it lost fuel pressure within 30 seconds, stalled, and then would not start at all. I pumped the ball for several minutes and still nothing, ended up having to trolling motor it for 45 minutes back to the ramp. On the way back, I periodically pumped the ball and tried to start it and still nothing.

After seeing the debris in the filter that was only a year old, I'm pretty convinced it must be debris in the tank which is causing this to happen. But, one question I have is why is the initial run always fine? it seems to only do this once the engine has been at full operating temp for a while.

My next step is going to be to drain the tank into buckets so I can see what trash may be in the gas, try as best as I can to inspect the tank once empty, and inspect the pick up itself. The boat is a 2002 Hewes Redfisher 21, so not only is it fairly old but I also know for a fact the previous owner did not take care of it at all, so I won't be surprised if there is just tons of garbage floating around in the tank.

[Moonlighter]

Ok you know you have contaminated fuel and its been causing fuel flow issues.

I agree with your plan to drain the tank and clean it out - there are some businesses that do “fuel polishing” services so it may be worth looking into that.

And with debris in the fuel for so long there is every chance that some of it has got past the filters into the VST. I would be getting it cleaned out too, there is, I understand, a little fine mesh filter in there that will get clogged up. Gunk in the VST can float around when the engine is off or at low revs, but when fuel flow is high, eventually it gets sucked into that mesh it gets clogged and fuel starvation happens. If you stop the engine it can loosen up and you can go again, until it blocks up again.

There is a high pressure fuel filter too that should also be replaced, usually a black metal one that is comparatively expensive. I know that you mentioned replacing filters as part of the trouble shooting, but if the tank has still been contaminated then they are likely to be full of gunk again too.

[booter]

I think what's happening is that once you start your run, it's stirring up the fuel tank and it's possibly clogging the screen on your pickup tube. Once you get your tanks cleaned, I would recommend getting a 10 micron fuel water separator filter between your primer bulb and the engine. I had a similar issue when I purchased my last boat used. On my '18 BC Lynx, I was having trouble getting on plane, but if I feathered the throttle when taking off, I was able to get on plane okay. At first I thought I had a propping issue, but when I changed out my fuel water separator, it was full of aluminum shavings. Once I put a new filter on, my hole shot issues disappeared and my 250SS runs like a champ now.

Lastly as summer gets closer and the water temp rises, I would also recommend idling for a few minutes after running WOT just to cool then engine off. During the summer, the 250SS will have issues vapor locking and you will have to either reprime the fuel system or crank your engine longer in order to start. Since the DF225 is similar to the 250SS, just something to remember.

[BumbleVee]

I have seen this same problem a few years back with another brand motor. Too long repair story to tell but pulled fuel tank sending unit out and there was a shop rag or something in tank. motor would run perfect till the fuel pick up hose would draw that rag to it. Shut it down every trip for a long time till we found it.

[Sirius Rich]

My guess is a high pressure fuel pump. Symptoms sound all too familiar and replacing bad HP fuel pump fixed it.

[Travelingbass]

Another update, I found some time to work on it between thunderstorms and here is what I have found out so far...

I siphoned all of the gas and removed the sending unit to inspect the tank and I found a surprisingly small amount of debris. The gas was almost completely void of any debris and when looking into the tank there was a very small amount of small particulates, but nothing that I think would cause so many problems.

After this, I checked the LP fuel filter (which I replaced last year) and it was very clean, then I worked on removing and disassembling the VST. The inside of the VST was basically spotless and the mesh pick-up screen on the HP fuel pump was clean, the float and needle also appeared to be in perfect working order. Then, I removed the fuel cooler and tried to blow some air through it but it turned out to be completely clogged (the water flow portion of the cooler, not the fuel flow). I ordered a new cooler and installed it when I reassembled the VST and put it back on the engine.

I have also been attempting to remove the fuel pick-up with zero luck; I've been through 2 cans of PB blaster and killed the battery on my electric impact twice and it has not moved a single millimeter so I've put that effort on hold temporarily.

Thus far, the only problem I have found was that clogged fuel cooler and that's it; the fuel lines from the tank to the LP fuel filter are all brand new, anti-syphon valve has been removed, LP and HP fuel filters have both been recently replaced, primer bulb has been replaced, fuel tank vent has been checked and is working properly, fuel tank has been inspected for debris, the only thing I have been unable to do is inspect the pick-up.

I am on the fence about driving 45 minutes to the lake to test it when the only problem I have found is that fuel cooler, and I seriously doubt that is the source of this problem, but I also am not sure about what to do next

[booter]

If you found that your fuel line cooler was clogged solid, I believe that was your culprit. The reason why is if you look at where your fuel cooler is at near the block of the engine, I feel that your fuel was system was vapor locking once the engine got hot from being under load since the fuel wasn't being cooled. Too bad Suzuki doesn't put a heat shield between the fuel cooler and the block or come up with a better design to prevent the fuel system from vapor locking.

[Travelingbass]

^^^It appears as though you were absolutely right about that. After putting everything back together, I was finally able to run it again and it performed without issue.

I did about 20 minutes of WOT and 20 minutes of idling during the heat of the day and experienced zero issues. I hardly knew what to do with myself, considering that was the first time I've been out with zero boat or engine issues in almost a year.

I'm weary of declaring victory so soon, but it's looking good. I really appreciate everyone who took the time to lend some of their expertise to help me out.

[Moonlighter]

It does sound very promising.

In your first post, you mentioned changing the fuel lines and the “in line filter”.

Im not 100% sure what kind of inline filter that your boat has, but ideally it should be one of the larger Racor style water separating filters, 10 micron with the replaceable element. I like the version with the clear bottom bowl with the drain, so I can readily see water/contamination and drain it off if necessary.

If you dont have one of those kinds of filters, I would highly recommend installing one, and changing the element no later than every 200hrs.

Anyway, fingers crossed for you that the problems are behind you.

[booter]

^^^It appears as though you were absolutely right about that. After putting everything back together, I was finally able to run it again and it performed without issue.

I did about 20 minutes of WOT and 20 minutes of idling during the heat of the day and experienced zero issues. I hardly knew what to do with myself, considering that was the first time I've been out with zero boat or engine issues in almost a year.

I'm weary of declaring victory so soon, but it's looking good. I really appreciate everyone who took the time to lend some of their expertise to help me out.

Glad to hear that thinks look promising and it was the fuel cooler. Even after running my '18 250SS hard at WOT during the summer time, I need to let the engine cool down for a few minutes or I'll have hard time starting it due to vapor lock.

[Alumicraft145]

Great thread. I learned quite a bit.