Bf225 not running correctly.

Hi,
I have a 2006 BF225
Lately my engine sometimes start shaking (RPM drop +-100) when it run.
This normally go away after 10sec-2min.
Most time is this happening when the motor have stay at idle for some time, or have stop for a wile and start again.
I hear/feel this shaking/rpm drop when I accelerate from idle, but also when I add some throttle in 3-4000rpm range.

I have change out the low pressure and high pressure gas filter, change out some gass hose, check thermostats, check/replace sparkplugs.
Yesterday I try when it shaken to add fuel pressure with the hose manual pump, but the was not any difference.

Earlier I change the exhaust pipe (Service 56) and a few O2 sensors, bidshaft bussing failure, change the timing belt, adjust the valve, change out the start cable wire, +++
When the O2 sensor fail, I usual get a alarm at idle.

Yesterday I also try to read out the code with a scs short connector.
I got then one blink every ca 3sec, I then reset it and it did not trow any new code at the dock.
Later I did a testrun and got some shaking/rpm drop and did a new scs short connector test, this time the Mil stay on and did not blink.

Any suggestion what to do?

First thing I would do is clear the fault codes, then run the engine again until it acts up, then see what codes you get, if any. You clear the fault codes from the ECM by activating the kill switch 5 times within 20 seconds. If successful, you will hear one or two beeps from the alarm.

Drain the VST in accordance with instructions in the owner's manual. If you get a lot of debris and/or water out of there, inspect/clean the high pressure fuel filter again.

Next check your fuel pressure. You do that from the fuel pressure relief bolt that sits on the side of the cover to the high pressure fuel filter. You will need a 6 mm adapter for your fuel gauge. Disconnect the vacuum hose to the regulator and clamp it closed. At idle (600 rpm +/-) fuel pressure should be between 41 and 48 PSI. When you replace the vacuum hose check it thoroughly for cracks or pin holes.

At that point also check the fuel lines at the regulator - the one to the fuel rail and the pressure relief hose that goes back to the VST.

Chawk, thank you for the reply.

I did try to drain the VST, and it was clear gas coming out.
I just use the hose that was there and opend the valve when the motor was not running and the ignition was off.

Do you think it is a fuel problem?
If so why do this usual happening in the start of the trip? if it was a bad hose/connection it should behave all time.

OK on the VST draining.

It does sound like a fuel problem based on your description, but you never know for sure. These are pretty tricky engines at times.

If you have a Helm shop manual, starting on page 2-15 it takes you through the diagnostic procedure for a rough idle.

Here is a link to an older online shop manual. It is in PDF format and can be saved to your computer. It's about 22 MBytes.

http://planbmarine.com/wp-content/u...ice-workshop-and-repair-BF175A-BF200A-BF2.pdf

In that procedure, it says to first check the IAC (Idle Air Control) valve and for a loose throttle body. Next check the IAT (Intake Air Temperature) sensor.

What colour were your spark plugs? An important part of a fuel pressure is after getting the system up to pressure with engine off, wait about 10 seconds and watch to see if the fuel pressure holds, if it doesn't, then you may among other things have a leaking fuel injector which can cause this issue because it will cause the O2 sensor to constantly try to lean the fuel mixture.If everything checks out, try a new O2 sensor, they can malfunction without logging a fault.

Just checked the mil with the scs short connector. I did reset it, and the MIL stays on after the reset. Isn't that a fault?

I also checked my gas pressure.
I removed the vacuum hose and clamp it, and start the motor.
It didn't run smoothly and the rpm did jump up and down. The pressure was about 3.2bar. about 48psi.
I removed the clamp and added the vacuum hose again and the engine running well again.

I take a picture of the sparkplug, but have problem upload it with my phone.

Now I do not know what next to check.

MIL light staying on is normal until you remove your shunt tool or wire. What did you set your valve clearances to? If they are correct then I would try another oxygen sensor

Ian's comment got me thinking? What is the make and number of the spark plugs you are using? This engine only runs properly using the NGK IZFR6F-11 irridium-tipped plugs. There have been problems reported with the Denso plugs.

Chawk, I using NGK IZFR6F-11 irridium-tipped plugs

I am using Honda 35655-ZZ5-004 O2 sensor (B22690, 40200-00 2x19), I think the earlier owner did change the O2 sensor to a other type I did remember that he mention there was a modification to get the new sensor to work.

Is that the best sensor to use?

Well, that COULD be the problem! I don't recognize that part number. It's a valid part number, but it's not listed for the BF 225.

What is the serial number of your engine? What is the part number on the ECU?

IF the upgraded HO2 sensor was installed, then you also should have had the upgraded ECM installed.

Here is what you should have IAW Honda Service Bulletin #70.

HO2S Kit 1 06356-ZY3-325
Kit includes
ECM 1 34750-ZY3-A04
HO2S 1 35655-ZY3-C01
Adapter 1 90074-ZY3-305

Ian - can you verify? Was there a further upgrade for the HO2 sensor for the 2006 (A6 and AKO) models?

Here is a pic of a few sparkplug I change out on my engine last friday.
https://www.dropbox.com/h?preview=IMG_20200524_111638.jpg

When I adjusted the valve clearance I used the spec the Honda manual come up with.

I was down to my boat today and read my serial number on my engine and that was: BAGJ-1400060

My ECM had number:34750-ZY3-A04, 7363-501206 and have name KEIHIN.

Can I then use a different O2 sensor?

35655 ZZ5 004 is old, that was discontinued about 4 years ago. 35633 ZY3 C01 has been used since. I would replace it and you will probably fix your problem

Dropbox insists that I sign up and download their app, which I will not do. The electrodes on the plugs should be a milk chocolate brown.

(Note: save the pictures in jpg, jpeg, or png format, downsize each to under 450 kb, and you should be able to upload it to this thread using the icon at the top right of this dialogue box - the one that looks like a screen, third in from the right.)

OK, you have the correct ECM for the upgraded HO2 sensor.

The question is: Do you have the correct HO2 sensor? According to Service Bulletin #70, you is should be PN 35655-ZY3-C01.

BUT it looks like that PN has been superseded by the one you have, PN 35655-ZZ5-004.

Can anyone verify that?

So we are back to square 1. If the HO2 sensor has failed again, then your plug electrodes should be carboned up and you should get a fault code "1". If either, do as Ian suggested and replace the HO2 sensor.

iang6766 said:

35655 ZZ5 004 is old, that was discontinued about 4 years ago. 35633 ZY3 C01 has been used since. I would replace it and you will probably fix your problem

Click to expand...

I can not find any part with 35633 ZY3 C01 number, do you mean 35655-ZY3-C01?
Do you think that is a better sensor that last longer?

Sorry, yes, 35655. I have had a few sensors causing rough running without logging a code. I'm saying, the ZZ5 sensor must be quite old unless it was old stock because it was discontinued long ago

Ian - thanks for setting us straight on that HO2 sensor.

Thank you very much for the help.

I just add a long order to boats.net, but when I should pay it was closed for international order do to covid-19.... so now I have to order a other place.

I also read about Honda have change out the manifold where the O2 sensor is placed higher, can that manifold fit my engine?

Today I start up the motor and just a few minutes at the harbor the known 02 alarm did start....so Ian did guess correct. It was the o2 sensor that started to fail buy did not throw any alarm until now. Next motor I buy I hope it doesn't have o2 sensor.