07 BF225 Long intermittent beep

Just purchased 07 290 Everglades. Got a good deal because the boat wasn't in the best shape and i'm currently working out the kinks. Had an inspection when I purchased for the loan and inspector mentioned Port motor wouldn't turn over 4,900 RPM. He did a compression test and everything came back good. About 3 days into using the boat at idle I got an alarm. It is a long intermittent beep. When I turn the engine off and restart its gone, but will eventually come back at idle, does not come back when running. From what I have read on the forms this seems to point to the 02 sensor. I replaced the O2 sensor with a new Honda 02 sensor 35655-XY3-013. (Motors are 07 BF225s), went out this past weekend and got the alarm on port motor again. Was just floating in the river tied up with a friend and I always like to keep one motor running so I turned the port motor off to get rid of the beep and left the starboard one running and after about 20 mins it now rang the alarm. Please help!

Side note: I haven't been paying attention to which light comes on when this alarm takes place, but for some reason I feel like the battery light might be coming on. When i'm out this weekend I will pay more attention to which light comes on.

Lastly: I read chawl_man's pulling dault codes article, so I did this tonight on both motors and got the same from each; the MIL light blinks. I'm assuming this is one blink, just repeating itself. From the code charts this gives me the following:

- Disconnected Oxygen sensor connector (this cant be it i know the sensor is connected)
- Short or open circuit in oxygen sensor wire (don't think this is it as the 02 sensor is brand new)
- Faulty oxygen sensor (don't think this is it as it is a brand new sensor)
- spark plug misfire (don't think this is it as the first thing I did after buying the boat is have it serviced and they replaced the spark plugs, they did say the plugs the pulled out looked like they hadn't been changed in a long time, but not sure this matters since they put new ones in)

Thanks in advance. After I figure out these alarms my next mission is to figure out why the port motor won't turn over 5K RPMs (think it has something to due with fuel delivery as I sucked by water separator dry and stalled the engine last weekend, after re-priming the filter it ran fine again)

Motors only have 515 hours

A code "1" can also be triggered by fuel pressure out of spec, which is 41 to 48 psi at idle. So check your fuel pressure. You do that at the fuel pressure relief bolt on top of the HP fuel filter cover. You will need a 6 mm adapter for your fuel pressure gauge. If too low, then you may need to pull the HP fuel pump and clean the screen on the bottom of the pump holder. If too high, the you may need to pull and thoroughly clean and test the fuel pressure regulator.

When is the last time you drained each VST? That should be done at every 100 hour maintenance interval.

When is the last time you changed the HP fuel filters. These engines are exceptionally sensitive to a clogged HP filter.

chawk_man said:

A code "1" can also be triggered by fuel pressure out of spec, which is 41 to 48 psi at idle. So check your fuel pressure. You do that at the fuel pressure relief bolt on top of the HP fuel filter cover. You will need a 6 mm adapter for your fuel pressure gauge. If too low, then you may need to pull the HP fuel pump and clean the screen on the bottom of the pump holder. If too high, the you may need to pull and thoroughly clean and test the fuel pressure regulator.

When is the last time you drained each VST? That should be done at every 100 hour maintenance interval.

When is the last time you changed the HP fuel filters. These engines are exceptionally sensitive to a clogged HP filter.

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Thanks for the input Chawk_man. Was hoping you would reply, you seem to know everything about these motors! I did just have the HP & LP filters changed with the "full service" I had done when I bought it. I dont know if they drained the VST through.

I was going to go buy a fuel pressure gauge from harbor freight as Skooter said he got one and it worked. Checking the fuel pressure will make sure everything down stream of the pump is okay right? I'm wondering if I have a fuel delivery issue since I lost prime in my fuel water separator trying to run WOT. Do you think this is the case. I did replace the separators tonight and noticed there was some old gasket material stuck to the separator mounting bracket. I cleaned this off, maybe this was causing it to suck air. I am going to give it another shot this weekend and see what happens.

Side note the mechanic said that Honda's do not have any way to monitor fuel pressure and therefore cannot throw a code if there is an issue with it. Does that sound right?

Well, the Helm manual says that if you get a code "1" one of the things to check is the fuel pressure, so the implication is that fuel pressure out of spec can cause a code "1." I have not personally experienced that, but I check fuel pressure about every time I pull maintenance.

If fuel pressure is within spec, then it says that fuel flow down stream from the HP pump is probably good. The one thing down stream that could still cause a problem are the injectors. But given your description that everything seems OK up to 4000 rpm, I doubt injectors are the problem.

One thing that happens at around 4000 rpm is that the Intake Air Bypass (IAB) is activated. The ECU sends a signal to the IAB solenoid at around 3950 rpm. That throws vacuum to the vacuum diaphragm that you see on the bottom of the intake cover on the back of your engine. (That's the diaphragm that you need to remove to get to the HP fuel filter.) When that diaphragm is activated it pulls open a set of baffles inside the intake, changing the amount of air entering the cylinders. Here is a write up on that whole process.

View attachment Honda 225 Intake Air Bypass.pdf

An inoperable IAB will not cause the problems you describe, BUT a disconnected vacuum line, OR a leaking IAB diaphragm, OR a leaking IAB solenoid will, so check that vacuum line very carefully from both ends, check the diaphragm for vacuum leaks, and check the solenoid for vacuum leaks.

When you are running a high rpm's, the fuel pumps are drawing a lot of fuel through the system, so if you had a bad seal on the external F/W separator , that could be the source of your problem.

BTW - for the record, I am not a Honda tech or a marine mechanic - just an interested owner who tries to do all of my own maintenance and repairs.

Update. Cleaned the gunk off the water separator mounts to get a good seal on the gasket on the separator filters. I ran it all day Sunday and no alarms!!!! You must have been right Chawk. Engine probably was having fuel pressure issue due to sucking air at the separators.

I'm still having an issue with my port motor not having full power. Here is what I can tell you. Engine starts and idles fine. I only start to notice the lack of power when I throttle up past 3,500 RPMs. At this point I have to push my port throttle a little further than my starboard to get the RPMs between the motors to sync. At WOT i'm only getting 5,200 out of my port. Starboard gets 5,700. I feel I would probably get closer to 6K out of the starboard, but I think it is making up for the port.

Any ideas where to start? One mechanic told me to look at my props. I thought this would be the last place I would look. Lets keep in mind I just had a full service. New HP & LP filters. New spark plugs, oils, ect...

Should I still start with fuel pressure?

Of course, look at your props and make sure they match and are not bent of nicked up too bad.

However, as I said before, check all of your vacuum connections, especially the one to the IAB - both ends. There are several, but I don't remember were they all are.

Okay, so checked props this weekend. They are exact same props (SS from Honda). Tiny knick on one, but there is no way this would cause this issue. Went to harbor freight and bought the fuel pressure kit they sell and checked fuel pressures. 40psi with the key turn and 39-40psi while running. (ps this kit screws right in not extra fittings needed)

I'm not too familiar with the IAB but did read a post on how to clean it so I have an idea of what it looks like i think. I did turn the cam with the spring back and forth. It seamed to turn very easily, and the spring easily snapped it back. The diaphragm looked good and was moving in and out when i was turning the cam back and forth.

I was reading this post tonight. https://www.thehulltruth.com/boating-forum/357661-honda-225-high-pressure-filter-help-2.html The issue tompass was having (topping out at 5200) is exactly the issue im having. The only difference is, i don't think my IAB is suck (as long as im guessing what the IAB is correctly)

Lastly, I would love to get the "helm" manual that has been mentioned in quite a few older post but can't seem to find it. All i can seem to find is the Honda Shop Manual, but its about $120 and don't want to get it, if it isn't worth it. I also see this company Solec makes a manual, but it seams like it is for all honda outboards, and feel i would buying a lot of info that wouldn't even apply to my BF225's.

Again, thanks for the help!

You need to get the official Helm shop manual. The aftermarket manuals have too many errors and omissions.

See this post: http://www.marineengine.com/boat-forum/showthread.php?461176-Shop-manuals

chawk_man said:

You need to get the official Helm shop manual. The aftermarket manuals have too many errors and omissions.

See this post: http://www.marineengine.com/boat-forum/showthread.php?461176-Shop-manuals

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Thanks Chawk. I downloaded the digital one to my iPad. Works great!

Any idea as to what I can stat checking next, now that my fuel pressure is good at the HP filter. Maybe the regulator? Can you check pressure here?

I assume that you are not getting any alarms or fault codes - correct?

With no alarms going off or fault codes to give you a hint on where to look, it's a crap shoot. Have you checked your vacuum connections and determined that the IAB is working correctly as I posted in #4 above?

Beyond that, the only thing I would recommend is a compression test and a leak down test. For the compression test, fully charged battery, all plugs removed, kill switch yoke pulled, throttle full forward, crank for at least 5 seconds to test each cylinder. Since you will not likely be working with a warm engine, expect to see about 165 - 170 psi on each cylinder. The highest cylinder psi should not be more than 10% above the lowest.

One other thing to check - make sure the fuel line to the port engine is not getting pinched where is goes through the big black grommet going into the engine compartment. Even a small bend or pinch will starve the engine under high demand.