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BF50D Fuel pump issue

I have the same problem lads vst stripdown twice high pressure pump replaced low pressure pump on its way nightmare now third vst to come out again so a can check out this grommet
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willste01 said:
Alan,

Your a legend. Reassembled everything and just back from a 4hr trip engine running sweet. I have a spare pump on route that I don't need haha but just glad it's working.

Can't believe it was down to that little rubber grommet!

Thank you to everyone who offered advice and suggestions.
Click to expand...
How much did you trim off the grummet
 
Dear all, I have exactly the same issue:
But the links above does not work anymore.
Could you please share the new link or show it on some pictures?
Many thanks in advance
BR
AM
 
Alan Hicks said:
So that's 3 of us just this year that frustration I experienced has helped.....

Surprised that issue isn't more widely known.

Makes you wonder how many pumps are replaced without legitimate cause.
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Hey Alan, I experienced this same issue about 5 years ago and had the high pressure pump replaced and the grommet. 4 years go by no issues. Now, having issues although not nearly as consistent as before but pretty similar. Not sure if it was the updated grommet or similar to the original. It was mentioned that the new Gromit appeared to be fixed by more firm rubber and slightly smaller than the original per this thread but I was wondering would you suggest still cutting it down a bit?

Very happy to have stumbled on this and appreciate forums such as these.
 
Yes same problem new high pressure pump ,but after pressure test, pressure fell away rapidly.removed hpsensor to find the sealer oring was kaput.so.will replace both pumps ,fit new. Orings to pressure sensor ect then see where we are.
 
Hi all,
I have the same issue exactly on my BF50D efi and want to carry out the same remedial action and trim the grommet, however having a look at the VST I am slightly phased by the task. I am hoping that someone on this post can help. Can the HP pump in the VST be accessed without removing the VST and if the VST needs to be removed can it be carried out easily. Perhaps someone with experience of this issue can help me through the procedure for removing the VST. A step by step guide would be great. Thank you all in anticipation.
 
It's easy, remove the intake complete with throttle body, then remove vst assembly.Make sure you cover all other fuel restriction possibilities first, it's not always the grommet
 
Thank you for your help. Is there a video or step by step guide I can get hold of. I now know that the air intake complete with throttle assembly can be removed but not sure how to go about that. Are the injectors and assembly left in position when removing the air intake? Just wish I knew how to go about it. Do I need to remove the bottom cowling to get access to remove the VST?
 
If you remove the bottom cowl you will find it's a very simple procedure. It's hard to describe a step by step without a motor in front of me.
 
Thank you I will need to have a look and see how to remove the cowl and then take it from there. I am in no rush as just need it fixed before my trips out next summer. My engine has done less than 50 hours and had the same problem after 25 hours running and was fixed under warranty. They fitted a new hp pump and and replaced one injector. Don’t think they ever considered the grommet problem which seems to be quite common. Thanks again for your very kind advice.
 
iang6766 said:
If your motor is still under warranty I would be taking it back and getting them to get it right.
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Hi Unfortunately the motor is 2016 so out of warranty. Still trying to find a video of how to fix. Will probably have to tackle the job and very carefully dismantle the VST. Thanks to everyone
 
Thank you all for posting this finding. I have the same issue. I may have used gasoline with ethanol in it and it must have affected the grommet. I ran the engine with a fuel gauge and could see fuel pressure diminish from @42 psi . 20 minutes after the engine warms up the pressure is below @ 5 psi and it dies. Engine cools down about 20 minutes and pressure starts to indicate as I turn the key and pump primes. Engine will start with about 15 psi showing . I’ll be pulling the VST shortly.
 
Yes this seems to be a common problem with these motors. I am still trying to source information on how to remove the VST. Would like a step by step guide but unfortunately information on line seems scarce on the Honda BF50D efi. Perhaps Some enterprising engineer will see the need and post a video for all us BF50D owners on how to remove the VST and access the grommet. I live in hope.
 
If you study it carefully with lower pan off you will find it's very simple.Take pics as you remove parts and reassemble in reverse order. Alternatively, buy a workshop manual, it will give you a step by step guide.
 
I also feel judging from your post, that you haven't covered all the diagnosing steps before attacking vapour seperator. This is one of the things with these forums, just because someone else had similar symptoms there are often many items that can cause the same problem. I have worked on these motors for a long time and I can tell you the grommet restriction is not a common problem. Fuel delivery to the seperator is the most common followed by build up of varnish as a result of lack of use and stale fuel, probably the reason for your failed injector that you mentioned, in which case a full fuel system service would be needed
 
Thank you very much for your very informative response. Much more to think about. The fuel is always fresh and the VST fills ok. The motor runs perfectly fine for 20 minutes or so then dies as iif it has run out of fuel and will not restart, but starts and runs perfectly the following day from cold. This happened before at only 20 hours run and was fixed under warranty. The engineer said he replaced the fuel pump and one injector. I am going to check and clean VST and pump as I think this is where the problem lies. Previous posts with same symptoms also point to the same problem so it will do no harm to check. Thanks to everyone again
 
Just try changing your fuel supply. The grommet issue usually restricts flow limiting RPM, motor doesn't usually cut out completely.Also try priming the primer bulb when it starts playing up and see if the motor recovers and runs properly again for a bit.
 
Hi
Changed the fuel supply and primed the primer which makes no difference. The motor runs ok for 20 or so minutes then stops as if running out of fuel. The primer remains solid throughout. Getting more convinced that the problem lies within the VST. It will be interesting to get to the bottom of this issue when I manage to remove the VST.. As you indicated fuel delivery to the VST can be the problem but i feel that fuel is getting to the VST no problem but it seems that after the motor runs for a while and heats up the pump in the VST is not getting the fuel through to the HP filter which is in good working condition. Think maybe it’s best to have a look and test the pump and make sure that the grommet is not restricting the fuel flow. As I mentioned before I just need a few pointers to help me carry out the removal of the VST. Cheers
 
Best to diagnose, you need to run the motor with a fuel pressure gauge to see what the fuel pressure is doing. Do you have warning lights and alarm.operatiing properly? I'm just not one for guessing, I prefer to diagnose and pin point problems.What I'm saying is, the few motors I've had with the grommet issue don't run properly right from cold and as I previously mentioned, still run okay at a lower less fuel demanding rpm. However I can only offer advice, it's very hard to diagnose issues without hands on .
 
Thanks for all your help. It is as you say very hard to diagnose without hands on, however it will do no harm to get the VST off and have a good look to eliminate pump and grommet problems. It will help me also to better understand the workings of my motor. It was so much easier with my old 2 stroke motors, things are much more complicated now. Will keep you posted when I get around to tackling the VST removal. Cheers
 
willste01 said:
Alan,

I whipped out the VST today and stripped it. Decided to test the pump with water while waiting on the new one.. the plastic cover/filter that goes around the pump was distorted and twisted I tried to pump water with it connected to a car battery and nothing. I stripped it off and tried and it pumped water perfectly free from the vst. Put it back together no water coming out. I loosened it a bit back from this grommet your talking about and boom water flowing perfectly. Thinking I have maybe wasted money on a new pump haha! drying everything out now and have trimmed the rubber grommet will put back together tomorrow and find out of it was indeed this causing the issue. Will let you know.
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How easy is it to remove VST as I have the same problem and have carried out all the checks apart from removing VST to check pump and grommet. I am looking for someone to guide me through the VST removal process. Where do I start and what is the easiest way to do it?
 
Gentlemen, thank you.from the bottom of my heart. Had the same High pressure pump outlet grommet issue. Took it apart and measured the grommet length compared to the cavity it sits in with micrometers and sure enough, it was bottom out. I cut back the end section so is bottoms out of the top flange and my fuel pressure is waaaay better
 
Barrabella said:
How easy is it to remove VST as I have the same problem and have carried out all the checks apart from removing VST to check pump and grommet. I am looking for someone to guide me through the VST removal process. Where do I start and what is the easiest way to do it?
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Fuel pump.png
Part #27 is the bit you want to cut back. Trim back to the ribbed section of the grommet.
Disconnect battery
Remove cowling
Remove fuel rail
Remove intake and note where the vac lines go
Remove the 2 bolts holding on the VST and pump housing.
Open up pump housing 5 bolts
Unscrew pump cage 3 screws
gently remove pump and offending grommet
Trim back to the last rib
Reassemble with some fuel compatible grease on the orings
 
Thank you so much this is the best information yet. I am a bit apprehensive on tackling the VST removal but now I know the sequence it will be easier. Would you be able to expand on the cowling and fuel rail removal for me. I Just need a little more information to help. I have carried out all the checks. Fresh fuel, Low pressure fuel filter clean, High pressure fuel filter replaced, Priming bulb remains hard throughout. Fuel is getting to the VST but after warm up it is not getting through to HP filter. I think that the Grommet is the problem and in any event trimming it would make sense preventing any future failure. It seems that quite a few owners have had this problem and I am disappointed that Honda has not recalled engines to have the potential problem fixed. Cheers again for all the help on this forum.
 
First up take lots of pics on your phone so you can see how it all goes back
so the timing belt cover comes off 4 bolts on a plastic cowling
Fuel rail has a single bolt holding on the high pressure fuel line fitting and 2 bolts holding down the fuel rail. fuel injectors need unplugging.
intake manifold has 2 nuts and 4 or 5 bolts at the end it attaches to the cylinder head, some are a little hidden. another 2 bolts up near the starter motor.
Disconnect all the electrical connections, they can only go back on one way due to the unique shape of each connector.
Disconnect the throttle link with a set of small pliers, just gentle pop it off in a straight outward movement.
Disconnect the electrical connection on the vapor separator.
Move the funny little hose clamps up each hose line so the hoses can slip over each nipple.
unbolt the 2 bolts holding on the vapor separator.
Turn upside down and spill fuel everywhere
Undo the 5 screws - use a flat head with pressure pushing down so you get a good grip and down strip the screw head.
Careful you don't loose any orings
undo the 3 screws holding on the fuel pump cage, down inside the reservoir.
Gentle remove fuel pump and offending grommet.
If you get stuck Impex has a full diagram of each part, linked below.
https://en.impex-jp.com/catalogs/outboard/honda/40/bf40d-lhd-efi-overall-14298.html
 
avh said:
Gentlemen, thank you.from the bottom of my heart. Had the same High pressure pump outlet grommet issue. Took it apart and measured the grommet length compared to the cavity it sits in with micrometers and sure enough, it was bottom out. I cut back the end section so is bottoms out of the top flange and my fuel pressure is waaaay better
Click to expand...

avh said:
First up take lots of pics on your phone so you can see how it all goes back
so the timing belt cover comes off 4 bolts on a plastic cowling
Fuel rail has a single bolt holding on the high pressure fuel line fitting and 2 bolts holding down the fuel rail. fuel injectors need unplugging.
intake manifold has 2 nuts and 4 or 5 bolts at the end it attaches to the cylinder head, some are a little hidden. another 2 bolts up near the starter motor.
Disconnect all the electrical connections, they can only go back on one way due to the unique shape of each connector.
Disconnect the throttle link with a set of small pliers, just gentle pop it off in a straight outward movement.
Disconnect the electrical connection on the vapor separator.
Move the funny little hose clamps up each hose line so the hoses can slip over each nipple.
unbolt the 2 bolts holding on the vapor separator.
Turn upside down and spill fuel everywhere
Undo the 5 screws - use a flat head with pressure pushing down so you get a good grip and down strip the screw head.
Careful you don't loose any orings
undo the 3 screws holding on the fuel pump cage, down inside the reservoir.
Gentle remove fuel pump and offending grommet.
If you get stuck Impex has a full diagram of each part, linked below.
https://en.impex-jp.com/catalogs/outboard/honda/40/bf40d-lhd-efi-overall-14298.html
Click to expand...
Thank you so much for taking the time to set out the procedure for removing the VST. This is just what I have been searching for and I am sure many others also. I now feel that I can confidently tackle the task with such clear information. I will take plenty of pictures during the procedure. Not going to tackle the removal straight away as I am away from boat at the moment but when I do I will let you know how it went. Once again I cannot thank you enough. Cheers
 
Just a heads up on problems with BF50 D high pressure fuel pumps. I purchased 2 motors with seized HP pumps.
Replaced them with aftermarket pumps & both motors would start , then die as fuel pressure dropped.
After trying to find the problem for two weeks or so I purchased genuine Honda HP pumps & couldn't believe
the result. Both my 2008 BF50D motors purred like a kitten. Just hope my experience may help someone
in the future if they need to replace a pump. I dont know why , but the ECM won't operate aftermarket pumps
on these motors.
 
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