Honda BF200 loss of power

I have a 2003 BF200 that previously ran great and suddenly we lost power and could only do like 1000rpms and motor was surging as if it was fuel starved until it totally quit running and we could not re-start. So, we performed a complete fuel maintenance by draining tank, new water separator and replacement of all filters. Ran Boat to lake and it ran great for about 10 minutes and then began to lose power again. The rpms would only do 2000 rpms and the motor was cutting out. After about another couple minutes I could only get about 1500 rpms and still motor was surging as if it was fuel starved ? Any ideas what could be causing this issue ? Thanks for the advice.

Regards, Mudrod
Texas Gulf Fisherman

Did you clean the fuel rails too? Also, did you check pressure on HP fuel pump?

We did not clean the fuel rails.... if they were clogged or dirty I think that the issue would happen right away. It seems that the motor will run great for about
10 minutes, then begin to bog down and eventually only get about 1000rpms out of full throttle. We followed the Honda service manual reccomendations for checking
the lp pump and the hp pump. The voltage check was good and the 2 ounces of fuel was good and the pressure seemed high, however we were unable to check actual
psi ? About ready to just replace the lp & hp pumps.... frustrated. Thanks for your help.

I believe there is a small screw that can be removed on the HP pump to check pressure. I remember reading it on here. CHawk and HondaDudecare pretty good at doling out advice. There’s a few mechanics on here too. They should be here shortly.

Are you getting any alarms? If so, is it continuous, long intermittent, or short intermittent? Are you getting any red lights on your key switch console? Have you tried to pull fault codes? If so, were there any?

10 minutes is about the run time you would get from the fuel that is in the fuel lines, the filters, and the VST, so my initial thought is that it's not a fuel pump issue but rather a fuel line obstruction, or air getting into the system.

So before haphazardly replacing parts, do some basic diagnostics...

1. When engine starts cutting out, open the filler cap to your fuel tank. If that clears up the problem, then the breather tube on your fuel tank is clogged. Small critters love to build nests in those breather tubes.

2. When engine starts cutting out, feel the primer bulb to see if it is partially collapsed. If so, and you have already tried #1 above, then you could have a clogged pick up tube in your fuel tank, a failed check valve in the primer bulb, or some other restriction in the fuel line between the pick up and the primer bulb.

3. When engine starts cutting out and you have already completed #1 and #2, rapidly squeeze the primer bulb. If engine performs better, then your low pressure fuel pump may be failing.

4. When the engine starts cutting out, look at your LP fuel filter bowl. It should stay about half full. If not, then there may be something restricting the fuel flow, or there is air getting into the system.

5. Install a piece of clear plastic hose in the fuel line between the external fuel water separator (assuming that you have one, which you should) and the on-board fuel water separator. When engine starts cutting out closely observe the clear plastic fuel line for air bubbles. If none, then connect the clear plastic hose between the on-board fuel water separator and the LP fuel filter and look for air bubbles. If no air bubbles, then connect the clear plastic hose between the low pressure fuel filter and the LP fuel pump and look for bubbles.

6. Finally, test your fuel pressure at the fuel pressure relief bolt that sits on top of the HP fuel filter cover. It should be between 41 and 49 PSI if my memory is correct.

If none of this identifies the problem, then come back at us for additional diagnostics.

BTW - Have you drained the VST?

Start at the bottom of page 1 on this thread. CHawk highlights the pressure and how to test the HP pumps pressure.

http://www.marineengine.com/boat-fo...er-dropping-off-under-load&highlight=Pressure

Thanks Everglades 260CC, I will give this a try.

Thanks chawk and everglades. I am Mudrods brother working on the same motor. Can you confirm the function of the fuel cut solenoid? Is it intended to cut off fuel when the engine gets too hot. Have you ever experienced it malfunctioning and restricting fuel under normal conditions? Again, thanks for your help. Very informative.....

Does it only do this under a load in gear pushing the boat? How does it behave it neutral? Will it rev in neutral?

You need to narrow it down to engine or power transmission to the prop. Behavior out of gear is the start of that troubleshooting. It alone won't give you the answer but it'll start eliminating things and narrowing down what you should be looking at.

The power loss will happen in nuetral or under load. The motor will eventually not even start and run. At which we have followed the service manual by testing
the low pressure fuel pump and the high presure fuel pump. Drained the vapor separator tank, checked all the fule lines for leaks and put it all back together.
We took the boat to the lake where it ran great for 10 minutes and then began the surging and loss of power again.

It sure sounds like some sort of fuel line obstruction or air in the fuel to me. Have you gone through the diagnostic protocol I described above?

Hi Chawk_man, Yes, us too. My brother will be coming over this Friday morning at which time we plan to go thru the procedures you reccommend. I will let you know
the outcome of those steps and advise. Thanks again for your help and support...

Regards, Mudrod & 65stang65

Are you using OEM coils? I experimented with aftermarket coils and they do crazy stuff. Almost impossible to diagnose due to their inconsistencies. Just throwing that out there just in case. OEM coils are hands down the absolute trouble free best.

Two more things to check, at times I have found the vapour separator breather blocked, this is the large hose running from the top of the VST .behind the intake manifolds, through a breather filter and then over the top and down to a barb fitting in the mount case which is vented to atmosphere. I have seen was nests in there which will cause the issue you are experiencing. Also check the fuel hose is not crushed where it runs through the rigging grommet, had this happen too.

That's very good advice from iang6766. In my previous post I neglected to consider the two items he posted above.

okay guys, ... Last week we found that there were air bubbles in the hose so we replaced the fuel lines from the tank pick-up to the water seperator, water seperator to the fuel bulb. Here is the latest after today's lake trial. Note: that we have installed a clear hose from the bulb to the fuel intake bowl inside on the motor. At the ramp, while boat is still on the trailer we could get the motor to rev up to 3100 rpms max and idle smoothly. When we placed the motor in gear the max RPM was only 2000 ?? Intermittenly, we would see some bubbles and then no bubbles for several minutes. We could not get the bubbles to consistently show up ? The motor seems to idle and run smoothly, we can no longer get it to surge like before yet, we can only get 1800-2000 rpms max. We have tried wriggling the hoses and checked all the hose clamps and cannot find where the air bubbles come from. Our next check is to pull the fuel pick-up tube and check it for cracks ..... any other suggestions as this is a real poser !!

Thanks for your help, Mudrod & 65stang65

Yep - the pick up tube could be the culprit. Also, it could be the pump up bulb itself. One other possibility is the seal on the fuel/water separator or the drain cock, if you have one. If you have a Racor, there are normally three seals, depending on the type you have - one where the filter screws on to the base, one where the bowl screws on, and one that seals the drain cock when it is closed. In fact, that would be the first thing I would check.The fact that bubbles are showing up some times and not others indicates an intermittent problem based on draw pressure. These are typically difficult to find, thus that's why I would first check those seals on the f/w separator.

Did you observe the level of fuel in the low pressure fuel filter while you were doing all of this? At idle, it should be well over half full. At high rpm's it will below half, but should still be very visible. At least that's the way my own 225 operates.

Why not bypass that part of the fuel system altogether and run a line from a 5 or 6 gallon external tank directly to the on board fuel water separator just to make sure the fuel feed lines are the only problem. And make sure you don't go out too far with just 5 or 6 gallons on board. At WOT - that beast will drink around 20 gallons an hour.

Guys, you need to take the guess work out of the equation, you still haven't confirmed you fuel pressure. To check if the vapor separator is actually running out of fuel, take a clear hose from the drain, open drain and hold the hose up, it will show the level in the bowl. I have been in this marine industry a long time and one thing I have learned is there is nothing more time consuming than guessing what is going on. The bubbles that come and go indicate to me that that is fuel separation in the pipe as the fuel starts to flow each time the float drops. Another thing I have experience is a blown high pressure pump o ring, again, can only be confirmed with a gauge. Also, when you have the gauge connected, turn the ignition on and off three times, leave it off after that and see if the pressure drops, if it drops quickly you have a major leak in the high pressure circuit, o ring, leaking injector etc. Can you also confirm your alarm actually works, it may even be overheating and going into guardian and you don't know it. Let us know how you are going when you have your pressure gauge

BF200 update : We are happy to say that we have been able to get the motor running smoothly yet, we have air bubbles in the clear tube test. About the rpm's.... it turns out that we miss read the back of the tachometer and had it set a for a V8 engine. After re-setting dip switches to the V6 we now get proper rpm readings. However, we still have air bubbles... after replacing the fuel pick-up tube. We started by using a clear hose from the bulb to the motor in-take and still bubbles, then we moved the clear hose to the external water separator to the bulb and still seeing air bubble.... so, lastly we bypased the entire system and went direct from the fuel pick-up tube to the intake and still seeing air bubbles..... we are baffled ? We used new fittings and used permatex fuel rated sealant on the threads and cannot figure out where the air is coming from ? any ideas about this. Also the fuel tank is 100gal... and we have a half tank of fuel. Any ideas of how we are still getting air thru the pick-up tube ? Thanks in advance....

Regards, MJ & 65stang65

Hi iang6766, we do not thin we have any issue with the VST or the pressure. At this time the motor is running smoothly and with power as we are now getting
31mph at 3000rpms. Our problem is with the air bubbles in the fuel line straight from the fuel tank ? see previous post about our issue and we would appreciate any
thoughts on how to figure this one out ? Thanks for your help...

Regards, MJ & 65stang65

Describe the type of pickup tube you have. Is it the straight hard plastic type, or the flexible "flop" type that has a weight and filter on the end to keep it in the bottom of the tank. If it's the former, they usually have some sort of gasket or O ring where it fits on the flange. Inspect that carefully for possible air leaks. If the latter, do the same inspection, plus the flexible section.

Also, you need to make sure that the fitting between the top of the pickup tube and the fuel line is pristine clean and properly connected.

We replaced the old tube with a new one. It is the straight hard nylon pick-up tube with a small screen inside at the bottom. It has two visible O'rings that are sealed and in good order. We cleaned the threads and applied a permatex fuel resistant sealant. We also replaced the fuel hose with new hose and new stainless clamps. Should not have any leaks but clearly we have the same amount of bubble as before. We only see the air bubbles when under full load, ... No bubbles when idling or under 1500rpms. Around 2200 rpms and above we get steady flow of bubbles ? Its a strange one ??

What happens when you use a portable fuel tank ?

Also, have you tried the clear hose between the pick up tube and the primer bulb? This is weird!

Air bubbles or fuel vapour ??----Many motors do have a vapour separator.---Must be a reason !

Try what chaw_man sugested bypass the mechanical low pressure pump it has a check valve in there this could be faulty

Tegweni - I think he is getting the air bubbles way before the LP fuel pump - back between the fuel line pick up out of the tank and the Racor.

Mudrod - Getting the bubbles only under full load may indicate failing seal or a connection that is not completely sealed. So if I am reading your last posts correctly you are getting the air bubbles directly from the new pick up tube - is that correct? And otherwise, the engine is now running well. Is that correct?

And you are absolutely sure that the connection to the pick up tube is completely tight - correct?

Is it possible the the new pick up tube is not going to the bottom of the tank and simply drawing in some air under high load conditions?

This is mudrods brother, co-owner of the boat. We found a lose fitting at the bulb that was causing the air leak�� Believing all was well, we made a 2 Day gulf run with no issues until the end of the second day when the motor cut out and died. We noted that the bulb was completely collapsed so we loosened the fuel tank cap but no change. To get home we removed the fuel pickup and used some extra hose to go directly in the tank and pump into the fuel line. The engine performed flawlessly for the 2 hour trip home. We since replaced the check valve at the fuel pickup and plan to make a couple hour lake run this week. Also note that although the boat comes out of the hole just fine and cruises at 27 knots, the rev limit peaks at 3000 rpm. Is this a rev limit in the computer? As always, thanks for your help......

The only rev limit on the ECU that I am aware of is the WOT limit of about 6200 rpm's.

There is an IAB vacuum solenoid that opens at about 3900 rpm's The vacuum solenoid opens the vacuum diaphragm that sits just above the HP fuel filter. If that vacuum hose is open on either end, or the diaphragm is leaking, or the hose has a hole in it, the engine will bog down above 3900, but will run fine under 3700 rpm. So check the hose and diaphragm.

We checked the hoses on each side of the IAB and found no issues. Just using my mouth, I tried pulling suction at the diaphragm port but only pulled air. The diaphragm did not move. Is this a valid test that the diaphragm has a leak or does it require a great deal more suction? Also, after insuring there are no more air bubbles anywhere, we got 50 miles out of the boat on an offshore fishing trip with no issues, then the motor cut out and died again. This time we noted that the engine mounted water separator bowl was full of gas(no water). When I drained it, the motor ran perfectly for about 8 more miles, then it was full again. Draining it again got us home with no issues. When back at home I connected a clear hose at the VST drain and performed the bowl test per your instructions. The gas level in the tube was about the same level as the top of the VST bowl. Could this be a stuck needle issue?