DT 225 no power under load

[bucknut32]

I have an 02 DT 225. Always ran great with no problems. Boat sat a year (seafoamed engine and gas). Got it out last week and changed out gas and all filters and fuel lines. Started fine (muffs). Took it out and powered on and will not go above 1300 RPM's under load. Will rev up in neutral. Mechanic said injectors clogged. He pulled injectors and had them sent out and cleaned. Got boat back (450 bucks later) and he said it ran great. I sea trialed it and it did the same thing and now it barely will idle. I checked the high pressure pump and it is good. Someone told me the Vapor separator has a screen in it and if its clogged motor will not power up under load or idle correct. I have no buzzers or check engine light coming on so I'm pretty sure its a fuel issue. Leery of taking it back to Mechanic cause he said he sea trialed it and it ran great. Any help would be appreciated. Thanks

[Harper]

My first inclination would be to clean the entire fuel system. And by cleaning, I don't mean run a can of Seafoam through it. Personally, I would never leave a boat sit for a year without completely draining the fuel tank and emptying the entire fuel system, especially if I were using gas with ethanol. I can almost guarantee that the fuel will go bad over that period of time, sitting in a tank that is open to the outside atmosphere (via the fuel tank vent).

So, I think you will have to clean the whole system; by draining the tank, disconnecting and draining the hoses, the fuel rail, the VST, replace or clean all screens and filters, and you might have to clean the injectors yet again, or replace them altogether.

Now that I've thoroughly disgusted you, I might be wrong........your solution might not be so drastic. My point is, you can't expect an outboard to run properly on gas that's been sitting for a year. The gas not only starts to turn into a varnish-like liquid (it even smells weird, not at all like gasoline), but if it contains ethanol, it will be absorbing water the entire time that it's exposed to the atmosphere. At some point, the alcohol reaches a saturation point, and you encounter phase separation, where the water and alcohol mix separates from the gas and forms a non-burnable layer in the bottom of your fuel tank. Seafoam is good for cleaning, but it doesn't prevent fuel from going bad in your tank. Sta-bil and other such products help a bit, but I wouldn't trust them to stabilize my fuel for a whole year. And none of these products prevent the absorption of water by the ethanol in the gas. Once the fuel reaches the point of phase separation, there is nothing that will fix it. It must at that point be disposed of. I use strictly non-ethanol gas in my boat, but I realize that not everyone is able to obtain it. Ethanol-laced gas is okay to use, but you have to burn it (not let it sit for months) as you would in your car, where you fill up every couple of weeks or so.

I wish you luck. I hope I'm wrong about the extent to which you will have to go to fix your problem.

[bucknut32]

Thank you for the reply Harper. You are right though, should have never left the fuel in the boat. I did fog the motor before I left but didnt drain out the fuel from the tank. I do use non ethanol fuel always as I know of the horrors of separation. I've already replaced all the lines from the tank back and all the lines in the motor (after draining tank). I pulled out the injectors again and bench checked them and they are good. I guess that leads me to the VST or the high and low pressure pumps. Guess I will replace the diaphrams and clean the filter in the high pressure pump and see where it leads. I was just curious if the VST could cause these problems. Thanks again for the response.

[Harper]

Yep, check that VST for sure.

[bucknut32]

Thanks Harper. Will post when I find problem. Much appreciated

[seaox230c]

The fuel pressure regulator is a simple system to test...you need a brass T fitting, a few feet of fuel line some hose clamps and a gauge that reads up to 50 psi. You put the t fitting in line between the regulator output and the input to the fuel rail, I will draw a diagram when I get home and see my rig. The last line off the T runs a few feet into the boat and gets hooked up to the gauge. If the pressure stays approx 25 psi at all ranges of throttle...I will look up the exact numbers later, then your filters/screens pumps and regulators are all ok and fuel is not your problem. There are finger filters at the inlet and output of your high press fuel pump . The pressure rig takes 1/2 hour to hook up and will show you if your fuel system is blocked or not working properly

[bucknut32]

Thanks Seaox, much appreciated. I think I know where you are talking about. The line from the Rail to the regulator. Great idea. Also, can I access the inlet and output screens on the high pressure pump or is it a sealed unit? Thanks again

[seaox230c]

The pressure is actually 36 psi and should not fluctuate much..one or 2 psi. Run 2 inches of tubing from the regulator to a T...the other line from the rail to the backside of the T and the last port goes to the gauge. When I ran my tests a while back the pressure was almost a perfect 36 at all throttle settings. If you take the pump out the filters are in the inlet and outlet. Thet are easily replaceable. See my posts...missing at speed by seaox230c I ran 15 feet of tubing so I could hold the gauge in my hand while driving the boat

[bucknut32]

Thanks so much, I like the 15 feet of line idea. I know exactly where now to put the gauge. Ill pressure test it but gonna clean screens first. Thanks a bunch.

[bucknut32]

Seaox, hate to bug you more but I saw a post where you were wondering about the brass fittings around the injectors and the 2 vaccum hoses along the fuel rail. Question is did you ever figure out what the deal is? I got 2 hoses connected at the bottom and none at the brass fittings above it. Just curious.

[seaox230c]

yes, I found those mentioned under a different engine model...those fittings are to be left open...the DT225 is a conglomeration of parts and systems from many different engine models and years...the descriptions for those systems are explained in the model where it was first introduced....its up to you to hunt down your system descriptions by reading the entire 400 page manual and picking and choosing the stuff that fits

[bucknut]

Just to wrap up this thread. All fuel delivery components were good (and or cleaned). Started motor (on muffs) and noticed the right bank was cool to the touch and the left bank was normal temp after a few minutes of idle. I checked the CDI and the right bank was getting no spark. Replaced the CDI unit and it solved the problem. Hope this will help someone in the future. Thanks for all the help guys.