2003 225 no power under load

I recently purchased a 2003 225 with 173 hours on it. It sat for a long time. Originally an alarm would sound at wide open throttle. I replaced the fuel pump, O2 sensor, and cleaned VST. I replaced the spark plugs, fuel filters, pulled and cleaned the gas tank and replaced the fuel line and bulb. Currently the engine starts and idles fine. When opening the throttle it start to pulse and surge under load. Pumping the fuel bulb does not change the problem. What's next?? Thanks

I assume that you are not getting any alarms or lights lit on your key switch - is that correct?

Start with the basics. When it starts to struggle, have someone feel the primer bulb to see if it is partially collapsed. If so, you have a clogged vent to your fuel tank, a clogged pick up tube in your fuel tank, or a malfunctioning check valve in the primer bulb.

Next, when it starts to struggle, have someone rapidly pump the primer bulb. If that clears it up, then you may have a faulty low pressure fuel pump or a collapsing fuel line going to the motor. If so, check where the fuel line enters the engine compartment to see if it is getting kinked or collapsing in that area.

Run with the cover off and observe the fuel in the low pressure fuel filter - it should stay around half full. If not, there there may be a restriction in the fuel line or you are sucking air into the fuel line.

If you have an external fuel/water separator, check the fuel line connections and the seals for the filter. If the filter hasn't been replaced for a while, replace it.

Get a piece of clear plastic hose with the ID at least matching your fuel line. Connect it between the primer bulb and the on board fuel water separator, run the engine until it struggles and look for air bubbles in the clear plastic hose. If so, track down the air leak. Next, run the clear plastic hose from the LP fuel filter to the LP fuel pump and look for air bubbles.

If none of that works, then you will need to inspect the other filters and screens in the fuel feed system. A list is attached.

View attachment Fuel filters and screens on BF 200 and BF 225.pdf

No lights or alarms.

Could if be a problem with the ECU? If so, how could I test it?

Thanks for the help.

These ECU's very seldom go bad. And the only really definitive test is to substitute a known good ECU.

Essentially almost all of the diagnostics in the Helm manual end with - if the procedure did not reveal the fault, "replace the ECU."

I have not had the chance to go through your recommended steps yet.

Looking at the filters on the pdf you provided, I have not inspected the mesh filter on the fuel pipe. From the diagram the filter looks to sit behind the fuel pressure regulator?

How likely is that this is my issue? Can I clean it or does it need to be replaced? Can I reuse the o-ring?

Thanks!!

That filter on the fuel rail only occasionally shows up as a problem according to the posts on this firum for the last several years. Plus, it's a pain to get to. I try to NEVER reuse O rings. But if in a pinch, try it. If you are going to go that far, I would also go ahead and pull the injectors and have them tested and cleaned.

There is a procedure in the Helm shop manual for testing the fuel pressure regulator. That's where I would look next. If you don't have the Helm manual, send an e-mail to me at [email protected] and I will send you a link to an online copy that you can open and save as a PDF file.

An 03 BF 225 with only 170 hours is bound to have problems.

I had a BF150 that was doing the same thing , it turned out to be clogged low pressure fuel filter. Also check out the high pressure filter, if it is brown it is probably clogged,sopposed to be green.

Jimmy Robichaud said:

I had a BF150 that was doing the same thing , it turned out to be clogged low pressure fuel filter. Also check out the high pressure filter, if it is brown it is probably clogged,sopposed to be green.

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I swapped out the ECU and there was a significant improvement. Interesting test drive today. I was able to get around 5000 rpm but no higher. It was still surging now and then. When I would turn to the left the surging would stop. When I would turn to the right the surging would get worse.

I am thinking there is a small air leak in the fuel line between the bulb and the motor.

What parts do I need to replace from the bulb to the water separator?

Thanks

See this link on boats.net: https://www.boats.net/catalog/honda...ca-vin-bahj-1100001-to-bahj-1199999/fuel-tube

BUT, surging does away on left turn and increases on right turn? That's screwy. Are you running with a near full tank of fuel?

Personally, if I experienced that situation, the first thing I would do is pull and thoroughly inspect and clean the fuel pick up tube in my tank. Possibly replace it. And when you put it back in. make sure it's all the way on the bottom.

chawk_man said:

See this link on boats.net: https://www.boats.net/catalog/honda...ca-vin-bahj-1100001-to-bahj-1199999/fuel-tube

BUT, surging does away on left turn and increases on right turn? That's screwy. Are you running with a near full tank of fuel?

Personally, if I experienced that situation, the first thing I would do is pull and thoroughly inspect and clean the fuel pick up tube in my tank. Possibly replace it. And when you put it back in. make sure it's all the way on the bottom.

Click to expand...

The tank was removed, cleaned, and new fuel line to the bulb. I am running the tank 7/8 full. The hose from the bulb to the engine has not been replaced. My thought is that when I turn to the left it kinks a hose a certain way that allows air to enter and causes the surging. I am going to replace the hose to the engine. I am having trouble telling which hoses I need to order.

I need the hose that connects #1 to the motor.



Thanks

You might be right about the line getting pinched because of turning. That usually happens where the fuel line enters the engine compartment through that big black grommet.

I think the fuel line inside diameter is 5/16 (8mm). There is no part number that I am aware of. Just purchase a top quality marine fuel line of that ID. There have been reports on this forum that typical auto fuel lines can collapse under high demand.