BF250 sluggish and then died. Fuel problem, O2 sensor problem, something else???

I purchased a 22 Bull Dolphin a year and a half ago with a 2013 BF250. Last summer after maybe 40-50 hours of use, I had to change the O2 sensor. That lasted about 25-30 more hours before it crapped out again. I am trying to remember exactly the symptoms, but I know the boat would not get over a certain RPM, maybe the 1500 range. I don't think it was sounding any buzzers, but I think warning codes were popping up on the gauge.

Honda found out there was a recall or something on the ECM, so they switched that with me paying labor. That was their first suggestion on the issue, second was fuel issues.

Since that work was done, have used the boat 3 times. First was a lunch cruise, probably a total 40 mile run with absolutely no problems. Second was a fishing trip, 80 miles or so, again no problems.

Took the kids to the river on Sunday. Messed around for a couple of hours, very little distance wise, and a mix of on plane running and on wake zones, and then after idling in a little cove and letting them swim, tried to get on plane and the RPMs were limited and then the engine died. I know the engine never died with the previous O2 sensor issues.

We were close to the ramp so restarted and just slow cruised back. (Another issue when we got all the way back to the ramp, in neutral the boat made an awful grinding noise. Nothing in forward or reverse. Cut engine and restarted and it was fine in neutral. Think I researched this as being a bad key switch. Does this sound right?)

I initially thought O2 sensor again, but since it died, I thought it could possibly be water in the fuel. I drained the FW separator in the bilge and it had very, very little water in it. I looked at the float on the engine FW separator and it did not appear to be floated off the bottom or have any water in it.

Does anybody have any thoughts. Apparently this hull isn't a fan of this motor with the exhaust ports, maybe, or maybe the ECM, or maybe it is a fuel issue. The first time I had the O2 sensor replaced by a boat mechanic that is a buddy, second was with the ECM replacement at a Honda authorized service center. They pulled the history and said the O2 sensor had been replaced 4 times already.

I know it is a boat and what that stands for, but I can't keep shelling out that kind of money on replacing O2 sensors constantly. I researched the issue about water getting into the exhaust ports, and this boat has a jack plate, so I have tried to be extra diligent about what running height (to make sure the ports are at least 6 inches above water line), coming off plane slowly, etc.

It is both frustrating to be chasing the ghost, and very expensive, so I am trying to do some of the investigation myself. I have done a ton of research, but I can't really find a lot about fuel issues causing the O2 sensor to fail, if that is the problem this time.

Your thoughts would be greatly appreciated.

If its an o2 sensor you should be getting an intermittent beep after 5-10 minutes after starting engine. The o2 sensor only affects idle and low speed operation, with a bad o2 sensor you can start the engine and immediately floor it and it will run fine till rpm's drop down again. With no codes being set it's gonna be tough to diagnose, maybe drain the VST then confirm good uncontaminated fuel supply by running off a portable tank with fresh gas.

Ditto - Pull fault codes, drain the VST, and change out the high pressure fuel filter. Contrary to the published maintenance schedule, the HP fuel filter should be changed every season or every 100 hours, whichever comes first.

You need to carry out some proper diagnostics. First as mentioned, check for fault codes, you have not once mentioned an alarm, does it work? Next is a fuel pressure check and then cam timing. These motors don't just die for no reason.

On a side note, careful with cheap Chinese O2 sensors. They either do not work or fail after a very very short time. Either purchase originals or Sierra Marine are ok too.

Thank you all for the replies. I tried to drain the VST yesterday but the drain screw is corroded and I am having to be pretty soft not to strip it. I thought I mentioned that there were no alarms, but any way, there were none. And on the prior o2 sensor change, it would run fine like you say until you dropped off plane, then RPMs would be severely limited. You could cut the motor off and back on and it would run fine until the next time. That also gave a audible beep. There wasn’t anything here. I am going to keep trying to get that screw to open for the VST and see what drains out.

Any tips on getting that out other than PB blaster. I did not try any heat yesterday, that was the thought for today. Thanks.

UPDATE: I was able to drain the VST, only about 16 ounces of gas came out, but it was clean, no gunk. I tracked down that the HP fuel filter was not changed at the last service. My plan is to pick one up tomorrow and change that out and then see how it runs.

OK. Let us know what happens at the test. AND, if not running 100% pull fault codes again.

Will do. Do you know if The paper clip trick will work on this motor- 2013 bf250. I have seen the pdf for the 200 and 225. Thanks.

I am fairly sure it will. Not sure that the fault codes are the same, but likely close.

It's the same but unlikely to find a code unless you've had an alarm.

I can’t figure out how to upload photos, but I could not check for codes with the paper clip because the red female plug faces directly away from this motor. I could get it off the holder, but there was not enough give in the wires behind to be able to get a paper clip where it needed to be.

HP filter was dirty but not collapsed. About to go run it and see. Thanks

These engines hate a dirty HP filter. Hopefully that will fix it. Let us know.

Ran it a little over an hour this morning with no issues. Hopefully it was just the HP filter. I did check the alarm history on the gauge this morning and it had an emergency stop and “high fuel” alarm from the last time we ran it when it gave us trouble. Definitely was not because of too much gas in the tank. Would that be a sign of the fuel filter? Thanks for all of your help with this.

Sorry for such a late reply but I thought I would give everybody an update. Other than running it on 4/4, which was two Saturdays ago, fished all day on 4/5 and 4/6, and then family time on 4/7 and 4/8. Engine ran great, no issues at all. I guess it was the fuel filter causing the problem.

One question though, I have the square single NMEA 2000 gauge, and when you look at the alarm history it shows the "high fuel" alarm mentioned above. I searched online but could not really find an answer to what that is. Any thoughts?

Thank you.