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'03 BF225 - 2 issues, oil leak and surging with low rpm's

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baytro23

Regular Contributor
I've got 2 issues I'm going to tackle when my parts come in. I used the search feature here and I believe my high pressure fuel filter is clogged on one of my 225's. The port is great and will go to 3500 rpm's wot when the other is just idling. The starboard will only to go 2900 rpm's and surges slightly. When cruising at 3500 to 4000 the starboard throttle has to be advanced farther to get the same rpm's, it also surges at that speed. Also with both throttles at wot the port is over 5000 but the starboard only goes to around 4000.

The other issue is oil leaks. 2 of the coils (luckily on same head) always have a drop of oil at the bottom. I've ordered the tube seals and the cover gasket. The oil leaks down into the case and runs down the back of the motor.

Any tips and advice is appreciated
 
Are you getting any alarms? If so, what lights are lite on your key switch when the alarm goes off? Have you tried pulling fault codes on each engine?

If you haven't changed those HP fuel filters within the last year, then they should be changed. Besides the HP fuel filter there are various other screens and filters in the fuel system that need to be cleaned or changed. Below is what I think is a complete list.

Fuel filters and screens on BF 200 and BF 225

• LP fuel filter 16901-ZY3-003
• HP fuel filter screen 16911 ZY3-010
• Fuel Pump Filter 16911-759-003 (on top of VST)
• Suspension strainer 16915-ZW5-000 (over top of fuel pump filter)
• Fuel Pump Insulator 16718-ZY6-013 (inside the fuel pump housing)
• Fuel filter mesh 16614-P5G-003 (on fuel rail)

Note: Fuel filter mesh 16614-P5G-003 is on the fuel rail. Item #4 as shown at…

http://www.boats.net/parts/search/H...er/BF225AK0 XCA/FUEL PIPE INJECTOR/parts.html

If cleaning/replacing those filters and screens doesn't do the trick, come back at us - there are other diagnostics and items to check.
 
Roger that.

These big Honda's seem real sensitive to having the correct fuel flow. Unfortunately, in the maintenance section of the Helm shop manual only the HP and LP fuel filters are addressed, but not all of the other fuel filters and screens. Furthermore, if the engine is showing poor performance because of abnormal fuel flow, the various sensors do not seem to detect that unless the HO2 sensor fails. The engine has over 16 different sensors, yet none of them address fuel pressure. Just my gripe for the day.
 
Replaced hi and low fuel filters and cleaned the screen on the rail (it had debris blocking over 50% of it). Emptied the water separator then blew thru it to make sure it wasn't restrictive. It's slightly better but still weak.

The seals did fix the oil leak.

I have the manual - where to now?

I couldn't find the fuel pump filter or the suspension strainer, exactly where are they? Couldn't find them in manual either.
 
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I did figure out the location of 5 & 6 but had not found 29 yet, thanks, I will check those 3 before giving up.

Something I did find: the water inlet hose that connects at back left (of VST) was pinched bad (no water flow) , what symptom will that cause?
 
I'm not exactly sure what symptom that pinched water hose would cause. I speculate that it would keep the VST too cool which in turn would effect your fuel flow to the fuel rail and injectors.

Hopefully someone else will chime in on that issue.
 
I checked 5 & 6, they're clear, was able to blow thru them easily. Also the screen (29) was clean...but I broke the hi pressure pump before getting it out. I barely punctured it on the side top.

At this point I guess I need to make sure compression is good. And actually measure fuel pressure.

Actually I don't think it's compression, when it surges it is strong.
 
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Well, the dolphin are starting to get thick and I'm tired of messing with this. I just ordered the hi pressure pump, O-rings, lo pressure pump, and pressure regulator. All brand new Honda parts from various sources for just under $350 for everything. Boat is 2 hrs away but I brought the manual and VST home with me. I will clean it and go thru the manual and check the float (I hope it looks ok when I get in there, didn't order that stuff). I hate changing all these parts at once since I won't know which one fixes it (to be sure it will be fixed after this). It's going to be a week or 2 but I'll report back.
 
Well, I got curious after work today. I JB welded the tiny hole I made and rigged an outlet tube and a pressure gauge to the hi pressure pump. I was really hoping it would go to 20psi or so. I wasn't brave enough to do the test with gas (and I knew I was replacing the pump regardless) so I dunked it in a pitcher of water for the test. The dang thing went to 75psi. Oh well, maybe the lift pump or regulator will solve it.

The float looked good and was within spec but I did reset it to 1.25". It was at the end of the range which shut off the gas sooner.
 
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Hmmmm. Don't know what to make of that. Fuel pressure should be in the 41 to 48 psi range (if memory is still working) measured at the fuel pressure relief port on top of the HP fuel filter.
 
Yes, I read in the manual it should be in that range. Just speculating here. I wondered if the pump WAS good and the higher pressure pumping water instead of gas has something to do with density difference between the 2 fluids??? Anyway, I suspect the hi pressure pump will not be the cure but I will have a new one in there so shouldn't have to worry about it again.

I'm hoping the lift pump is weak and can't keep up with demand. One thing I haven't done is bypass the fuel bulb, I know those things go bad.

How does the pressure regulator work?
 
VST has been cleaned, float set, and new hi pressure fuel pump - new low pressure (lift) pump - new fuel pressure regulator - test ran and no difference. I was convinced I had a fuel flow/restriction issue. I'm not sure what took so long but I finally pulled the plugs and 5 looked normal and the top starboard side plug looked brand new. I researched that and found that a shiny white insulator means the plug is overheating, i.e. lean. At this point I believe it will turn out to be that injector, wiring harness, or ecu. At first I thought maybe that plug wasn't firing. I pulled it, the coil, and grounded it. Then I started the engine and had good spark. I have not checked compression but running with the missing plug it sounded like it had plenty.

Oh well, I believe I'll have it solved soon. I've got some spare parts now and have learned a lot about my engines.
 
I replaced that injector with a used one. I makeshift tested it before install. No difference. I am reluctant to do anything to the good engine but I did swap spark plugs and coils on #1, no difference.

I did discover that I do have the surging from about 2300 to 2900rpms in neutral with no load so now at least I don't have to run the boat every time to see if it's fixed.

I verified around 10 ohms to each injector from the plugs at the ecu.

I'm going to try to actually monitor the fuel pressure and get the 6 injectors professionally cleaned.

I feel like pulling the 2 fuel rails, then put the engine back together enough to turn it over, and verify I get 6 squirters.

I can see the 2 intake valves but I can't feel the port that the injector sprays from. My daughter is bringing me a dental inspection mirror home from work. Also when I pull the rails next time I will push a flexible tube into the injector port to verify it's open and has access to the valves.

Still frustrated.


Also, I bought a ecu off e-bay a yr ago. Might as well try it too.
 
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Tried the ecu, no difference. Pulled the injectors again and tested them pretty well with proper sized tube and a hose clamp on one end and sealed tube from carb cleaner can on other. Beautiful spray pattern from each injector. No difference. I exchanged 3 plugs and coils from good engine, no difference. Then I exchanged the other 3 and it seemed to make a difference.

I'm going to try 6 new plugs and do a compression check. If the plugs don't do the trick and the compression checks out then I will send the injectors out for a pro check.
 
At this point I think it is time to back up and re-think this problem. In your initial post you talked about where the rpm's are and the starboard engine is surging at around 2900 rpm's. But "the port is great and will go to 3500 rpm's wot when the other is just idling." Specifically, what do you mean by that?

What happens when you try to run them out to the full WOT of around 6000 rpm's?

Just how much is the starboard engine surging in terms of high and low rpm's?
 
My boat is a 28', pretty heavy, deep V cc and has 19" pitch props. It won't plane on one engine. The good engine will go to 3500 rpm's by itself and the bad engine will eventually get to (what ever I said, under 3000).

This is embarrassing, I replaced all 6 spark plugs and can't get it to miss/surge in neutral (2500-3000) like it has been doing. I'm optimistic that it's solved. I'll know for sure tomorrow after I run her.

I've been doing all my own maintenance and repairs on my cars since 1979. This is the very 1st spark plug I've seen bad. I've changed lots (for preventive maintenance) but never had one make a difference.

Oh well, like I said before, I've learned a lot about my engines and have some spare parts now.
 
Roger that. These big Honda's need to be run at WOT at least occasionally to keep them in good shape (valves & rings properly seated) and blow out carbon and gunk. WOT needs to be around 6000 rpm +/- 300. Otherwise, you are putting a lot of strain on the engine. I suspect you may be seriously over propped with those 19" pitched props.

I'm running a heavy 25' C Hawk (6000 lbs, loaded) with a single BF 225 and had to go down to a 14.5d X 15P prop to get it to 6000 rpm when new. At just under 2000 hours, I get 5800 rpm's at WOT - 38 mph on flat water. If I remove the Lee outriggers, I get 5950 rpm's and 40 mph.
 
Good news, It was indeed the plugs. Runs like new again. Props are good. With both engines contributing my wot is 6200 @ 40 kts light. My boat is long and heavy but it's narrow, only 8' wide. It's a Master Marine (Good Go 28). I was just saying I only get 3500 rpm's if I put one engine in neutral, just as a short test. Now they both rev up at the same rate and reach the same wot and either motor will go to 3500 when the other is in neutral.

I'm happy but disappointed in myself but like I say, this is the very 1st plug I've actually seen bad. But...I've never owned anything with NGK plugs before either. I think I'll try to cross them to AC DELCO

Thanks for everybody's help.
 
That is indeed good news. Don't feel bad about that. You are not the first, and certainly will not be the last to find that bad plugs were the source of the problem.

Would suggest that you stay with the NGK's. For some reason, this particular motor and most of the other Honda's do not perform well with the Denso's, which is the ONLY recommended substitute. I have no idea why that is, but every Honda Tech I know says NGK's only. They should be good for at least 400 hours, but I'm sure that occasionally, they will not go that far.

As a matter of procedure, every time I pull 100 hour maintenance, I also pull the plugs, inspect them for that light brown coating on the electrodes, and then put a thin coat of high heat grease on the threads upon re-installation. That assures that the stainless steel plug base never welds to the aluminum head and makes subsequent removal very easy.
 
Thanks for that reassurance. I was 1/2 joking about switching to AC DELCO. I've owned primarily GM vehicles in my life but the occasional Chrysler product (Dodge trucks). I do know certain brands work only (or at least better with) certain plugs. Chryslers like Champion.

One more question - I got plugs from Autozone (NGK's for a Odyssey) with a heat range of 5. I should probably order the correct ones, right? After I did the compression check (all 6 180-190) and then switched plugs from the good engine with encouraging results I just had to get 6 new plugs (anything that would work) in there to know for sure.
 
I put 12 new spark plugs in and tested properly. Went 25 miles offshore this weekend, the bad engine (one I've been working on) ran flawlessly, not a single hiccup. The good engine actually surged ever so slightly at mid to hi rpm's a couple of times early on in the trip. I ran out at 3700-3800 rpms @ 27 kts. I came back in at 4000 rpm's @ 30 kts and I don't recall any surging. Gunna change the low and hi pressure filters in it anyway.
 
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Well, that's certainly good news. Sounds like you are about to be a happy boater.

These 225's are great engines if properly maintained.

For several years, I was getting a 100 to 150 rpm surge in my engine in the 4000 - 4500 rpm range. Everyone was telling me that was the VTEC trying to figure out when it should kick in or not. Turns out that the baffles on the intake air bypass were stuck closed. I ended up having to replace the entire IAB because it had become so corroded. Surging went away. If you are interested in the bloody details, send me an e-mail at [email protected].
 
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