Problems with my DF50

[Wcummins1313]

Hey Guys,

First and foremost, I'll get it out of the way. I'm not great when it comes to mechanics. Take it easy on me for stupid questions....

I'm having issue with my 2008 DF50.

It started the other night. My wife and I were just getting back to our dock from our evening pontoon cruise. I decided to open up the motor a little bit before we went back. The motor started to sputter at higher speed, but it ran fine at lower speeds.

I took it out the next day and found it to be sputtering at all speeds, but definitely worse at high speeds. It's definitely intermittent. It seems to run best best at low speeds, but will eventually stall in neutral.

I'm not a complete moron and figure it has something to do with a fuel issue.

I noticed the hose and connector going into the motor has a slight drip, so I replaced that (no change).
I ran some seafoam through the motor (no change).
I emptied the gas and put fresh stuff in (no change).

Short of buying a new tank and hose, I'm running out of things that I readily know how to do. I have the manual and can figure out most repairs from that and Youtube. The problem is, I have NO idea where to start. According to the manual, it could be any of these issues:

Possible cause : • Incorrect by-pass air screw adjustment [NOTE3] • IAC valve failure [NOTE3] • IAC passage failure (clogged hose / silencer, etc.) [NOTE3] • Spark plug failure • Ignition coil failure • ECM failure • Wire continuity / connection failure • Failure of high pressure fuel system components : • Fuel injector (clog, stuck valve, etc.) • Fuel pressure regulator (incorrect regulated pressure, etc.) • Fuel pump (clogged suction filter, leakage in tank, etc.) • Fuel filter (clog, etc.) • Hose (clog, kink, leakage, etc.)

Any idea where I should start?

[Moonlighter]

I would be looking at fuel contamination based on the symptoms you described. Spluttering at higher speeds is indicative of fuel restriction (eg clogged filters) or lines, or air getting into lines. And it only ever gets worse as the contamination clogs things up more.

First I would change out all the fuel filters. Then the fuel lines. With some luck you might have got it before it got further….

But it might have got into the VST and clogged things up there. Im not familiar with your 50 but the VsT usually has a little filter screen inside it too. So if the filter change doesn’t solve the issue then the VST might be the next step.

Do you have a filter on the line between the tank and the engine? I know many people dont do that on boats with portable tanks, but really its just good insurance. All of us with larger motors and underfloor fuel tanks use such filters eg RACOR style that have the clear bowl so you can see water and contaminants.

Good luck and dont forget to ket us know how it all tuns out. That way others get to learn about things.

[Moonlighter]

I would be looking at fuel contamination based on the symptoms you described. Spluttering at higher speeds is indicative of fuel restriction (eg clogged filters) or lines, or air getting into lines. And it only ever gets worse as the contamination clogs things up more.

First I would change out all the fuel filters. Then the fuel lines. With some luck you might have got it before it got further….

But it might have got into the VST and clogged things up there. Im not familiar with your 50 but the VsT usually has a little filter screen inside it too. So if the filter change doesn’t solve the issue then the VST might be the next step.

Do you have a filter on the line between the tank and the engine? I know many people dont do that on boats with portable tanks, but really its just good insurance. All of us with larger motors and underfloor fuel tanks use such filters eg RACOR style that have the clear bowl so you can see water and contaminants.

Good luck and dont forget to ket us know how it all tuns out. That way others get to learn about things.

[Moonlighter]

I would recommend looking at fuel contamination.

This is based on the symptoms you described. Spluttering at higher speeds is indicative of fuel restriction (eg clogged filters) or lines, or air getting into lines. And it only ever gets worse as the contamination clogs things up more.

First I would change out all the fuel filters. Then the fuel lines. With some luck you might have got it before it got further….

But it might have got into the VST and clogged things up there. Im not familiar with your 50 but the VsT usually has a little filter screen inside it too. So if the filter change doesn’t solve the issue then the VST might be the next step.

Do you have a filter on the line between the tank and the engine? I know many people dont do that on boats with portable tanks, but really its just good insurance. All of us with larger motors and underfloor fuel tanks use such filters eg RACOR style that have the clear bowl so you can see water and contaminants.

Good luck and dont forget to ket us know how it all tuns out. That way others get to learn about things.

[ECU1984]

I would drain vst tank and replace filter on powerhead, change plugs (cheap and easy)

[Wcummins1313]

Hey Guys,

Think I may have solved the issue.

I bought a new tank/fuel assembly. I also replaced the plugs…they looked in pretty bad shape.

There was some debris in my old fuel tank, which has me worried a bit. If I have any more issues, I’ll replace the filters like you guys recommended. For sure this fall when I take it out.

[tommybe1]

i had a similar problem that the good folks here helped me with. Had me replace the connector off the tank and the one going into the motor. Both were clogged with white gunk. Then ran a can of sea foam in a one and a half gallon can filled the rest of the way with gas straight to the motor. All was well after wards. good luck. love the df50/