Logo

Bf225 cuts our/starves for fuel after running wot for 10-20 min

Mitchrm

New member
Hi my bf225 started acting up recently. It runs and starts fine but after running hard wot for a while it starts acting up. Non ethanol premium is being used, new plugs this spring and completely went through the fuel lines from the engine to the tank. Replaced hp fuel filter. I get no alarms. I still need to bypass the primer bulb because I don't trust it, just to make sure. Vst has always drained clean and clear. Any suggestions? Coil? Lp fuel pump?
 
Is your engine running warmer than usual,can you hold your hand in telltale stream indefinitely? Why haven't you replaced primer bulb
 
Could be one of any number of things. Are you running any add on water separators like Racor filter? If so, that's where I would start looking. But you're right not to trust the primer bulb. Bypassing that is a good idea. LP pump is a good guess too along with johnnygjr's running hot suspicion.

Sounds like you're just going to have to start eliminating things one at a time.

Good luck.
 
How is it "acting up"? Specifically, what is the engine doing?

Here are a few diagnostics that will get you going...

If you have an external fuel/water separator (e.g. Racor), drain it, or replace it if it has not been replaced in over a year.

Check for overheating. However, an over heat will normally throw an alarm if the sensors are working. You can confirm that you are not overheating by using an IR temperature gun. When it starts acting up, remove the cover and check the temperature on the heads. They should be around 160 F.

Not having the primer bulb hooked up prevents you from testing a few other things. If it is hooked up, when the engine is acting up see if the primer bulb is partially collapsed. If so, then you have a clogged vent to your fuel tank, or a clog in the pick up tube inside your tank, or a malfunctioning check valve in the primer bulb.

Again, with the fuel bulb hooked up, when the engine starts acting up, rapidly pump the primer bulb. If that clears up the running for several seconds, then you can suspect that the LP fuel pump may not be functioning properly.

Where your fuel line comes out of the LP fuel filter on its way to the LP fuel pump, splice in a clear plastic tube with the same ID as your fuel line. When the engine starts "acting up" closely observe that clear plastic hose for air bubbles. If so, you need to back up through the fuel lines to check for air leaks. First check the connections and seals on the LP fuel filter and the on-board fuel/water separator. If you have a quick disconnect on your fuel line as it comes into the engine, check that carefully. Check the connections and seal on the external fuel water separator.
 
I just installed an add on filter, after the first trip I noticed trouble, the same time I replaced the hp filter. So the problem occurred before the add on filter. I haven't checked the tell tale temp, good idea.

The engine sputters as its running out of fuel, almost tosses you out of the seat. When I back off the throttle a little it will stabilize and rUn fine. As if not enough fuel is delivered to keep up with the demand.

I have a separate fuel pickup from my tank and it does the same with that. The primer bulb... im going to bypass with a straight line directly from the tank. I do run my fuel through a lowrance fuel meter and this will eliminate any problems with this also. The primer bulb just don't seem right. I got to squeeze it a lot and it feels like it is swelling, getting bigger under presser when the engine is running. I just want to take it out of the equation.
I do have an external fuel pump that I used to check for air leaks. I sucked about 40 gallons of fuel through the system. Testing every component and every line. A lot of air when gong through components, filter, paddle wheel, barb fittings. It seems as the vacuum makes the air bigger. So I hooked up to push fuel through hoping to find a leak, or seep of fuel. Nothing. Fuel flowed much better with no air at all. 8 hours of testing fuel lines.
After I bypass the primer bulb and all the installed components and there is no change, I'll thinking to remove the vst and look for a restriction there. It's always drained clean and clear tho.
Parts diagram shows a filter behind the intake manifold. Is this just a fuel breather filter? Or is fuel pumped through it?
Thanks for any suggestions and help. I dI'd a lot of searching on forus but nothing matches my exact problem.
 
What year is your BF 225?

Do I understand correctly that your problems started just after you installed and external fuel/water separator? What make was the filter? Does it have a flow rate of at least 30 gallons per hour? Was it a 10 micron? If it has a screw wheel drain on the bottom, is that tight and correctly sealed? Have you tried bypassing it to test whether that is the source of your problem?

When you replaced the HP filter, did you also replace the LP filter? If not, I recommend that you do so. You might want to take another look at your HP filter. Make sure that the spring behind the filter is properly in place, that the flimsy little O ring is properly seated, and the bolts are torqued properly.

Does the problem start at a particular rpm?

If the primer bulb was getting really tight and "swelling" while running, that is really strange. I've never come across such a situation. Why not replace the primer bulb with a new one? They don't cost much. And that is a quick and easy way to check whether your LP fuel pump may be failing.

Take a piece of string cleaner mono and run it in and out of the vent on your fuel tank breather just to make sure it is not partially blocked.

I'm not sure that using an external fuel pump to suck fuel through the system is going to tell you much. The fuel pump on that engine is one powerful pump. A pin hole in the line or a connection that is not totally sound will pull air through the fuel system. Try the clear hose procedure.

I do not understand you statements "It seems like the vacuum makes the air bigger" and "Fuel flowed much better with no air at all." What do you mean by all of that?

If you do remove the VST carefully inspect the float valve for corrosion or scoring. It's possible it could be sticking. But if it sticks closed, it will cut off all the fuel to the engine.

I'm not familiar with the "filter" behind the intake manifold. There could be one there, but I've not come across it. I looked at the parts diagram for the intake manifold and did not see a filter. See link below.

http://www.boats.net/parts/search/Honda/Outboard Engine/2005/BF225A5 XA/INTAKE MANIFOLD/parts.html

There is a fuel filter screen under you HP fuel pump that can get clogged up. It's inside of part #29 in the link below.

http://www.boats.net/parts/search/H...06/BF225A6 XA/VAPOR SEPARATOR ASSY/parts.html

Last year Seachaser was having a fuel issue that he finally traced down to a fuel screen on the fuel pressure regulator. See thread and pictures in the link below.

http://www.marineengine.com/boat-fo...utboard-225HP-Engine-Light-quot-ON-quot/page2.
 
The problem started before I installed the external filter. I had the filter since I got the engine and never installed it until after I incountered this problem. It is 10 micron. The hp filter I didn't know was even there until I read through the service manual after the problem started. It was dirty, not distorted out of shape like ones if seen on here but had a very dark residue on it. I replaced it. The low pressure fliter was fairly new. And looked fine. But I just got done replacing it a few mins ago. And I also ran a line directly from tank to engine. Brand new line. I will also install a clear hose between the lp filter and pump. To watch what is happening there. I agree the external pump I used was an inferior test for sucking air into the lines. Based on my observations. My goal there was to see if the lines were getting blocked or plugged or maybe a pickup tube was cracked, and I assured myself this was not the case.
Sorry for being long winded, but I'm tring to answer all your questions asI read your post.
Hmmm. I think that little screen under that hp filter may be what I'm looking for! As dirty as the hp filter was that's got to be starting to clog up. That's my next place to look. Then the other screen you mention above. Thanks for the links. Ive read about these screens but wasnt having any luck locatin them.
 
Same thing happened to my starboard motor, run it at WOT (5600~5800rpm) for about 2 minutes and it acts like coughing and then cut down to 4000 rpm. If I back down to 3000 rpm, and then go WOT again, it would only go up to 5000 rpm and surging a bit. If I pull the engine back to idle, wait for a few minutes and then go WOT, it would go over 5600 rpm again, but a couple of minutes later the same thing repeats itself. No warming light or buzz. My engines can run all day at 4400rpm so I am not going to do anything now. It will be my winter project to clean the screen under the HP pump and see if it helps.
 
Sounds like a very similar problem. Mine will just try to run at wot 5800 rpms. It won't decrease rpms on its own. Keep in touch! I'm going to pour myself some coffee and go see what I need to do to inspect this screen. I hope I don't need to remove the intake manifold...
 
Vst and hp fuel pump screen, was clean as a whistle. Havent test run yet. Only with muffs, noticed fuel level stays very low in the low pressure filter when running muffs. Is this normal?
 
I can't tell you definitively where the fuel level should be in the LP filter bowl. However, on mine it stays above half full at idle. As long as it has some fuel in there, I don't think it's critical.

If you have an external fuel/water separator and it hasn't been changed for a while, then a new filter might help.

Also, the on board fuel water separator has a type of filter cup in the top of it - it's sort of a funky looking contraption. Pull that out and clean it with alcohol and gentle compressed air. That might improve your fuel flow.
 
Ok so here's an update, I been busy installing a kicker motor and final got it finished. :) Now I'm back to troubleshooting my problem. I tried the clear hose after the low pressure filter and I'm getting a lot of air. Lots! So I'm going back through my fuel lines. I did this test with a line straight from the tank, still through the primer bulb. ( I know... I was going to swap it with a hose but I left it with my tools back at my shop...) next trip I'll keep moving the clear hose in the direction of the tank until I find the source.
 
Hope the video works. This is at idle with muffs. Not much different on the lake while under way.[video]https://www.facebook.com/ralph.mitchell.148/videos/vb.100001350081491/1066636943391298/?type=2&theater[/video]
 
Video didn't work.

You stated: "I tried the clear hose after the low pressure filter and I'm getting a lot of air. Lots! "

You just need to back up through the fuel system and find where that air leak is coming from. Several weeks ago we had someone on the forum with the same issue. It turned out that when he accelerated, the fuel line pick up in his fuel tank would suck air because it was installed incorrectly. The pick up tube was set too high.

It can be any number of things - bad clamp, pin hole in the tubing, bad seal at the LP fuel filter or the on board fuel/water separator. It's a bug hunt.

Keep us posted.
 
I think i got it tracked to the fuel line that enters the engine. The line that connects to the water seperator. I have a barbed fitting in this line that i disconnect to introduce a winterized fuel mixture for when i put it up for winter. I idled the engine testing each component up to this point where i began seeing significant amounts of air. I replaced this line with a clear hose and sucked fuel out of a quart jar and the air was greatly reduced. So i got parts coming. New primer bulb line, new line that enters the engine and an anti siphon valve (mine doesnt have one, or the insides have been removed, i visually checked) Im hoping that the anti siphon valve will help work as a check valve, and also needed for the safety aspect. Im excited to test it out when the weather clears up.
 
Sorry for the late reply. My problem is resolved and engine runs strong.
A pin hole was found in a location that I disconnect the fuel line for winterizing purposes. I traced air bubbles to this point with a clear hose. I thank everybody for the help and guidance.
 
Back
Top