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Bf150 fuel supply issue?

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Bustedknuckle

Member
Hello,
I have an 2019 Clearwater 2508 with Twin Honda BF150s and only non Ethanol has ever touched these motors. It has been about 9 months since I have taken the boat on water. Port engine runs fine. I'm looking for help on my recent trip. My starboard motor would run up to 3500 rpms for about 5 seconds trying to plane but then lose rpms and die out. I can restart the engine again fine and runs up to 2000 rpms fine but nothing more. If I turn it off for a few mins, I can run it again over 2k to about 3500 again before it starts to die out. I have done the following services. 1. Recent Engine oil change
2. Water fuel separator was changed in the last yr,
3. Low pressure and high pressure fuel filters have been changed out. within last 9 months.
Is this a symptom of the VST not getting enough fuel supply in and starving the engine. If so, would that mean I'm looking at the low pressure pump or could the hand bulb have a restriction in it? I had to replace the Port sides hand bulb for a different issue already.
Or is this a complete different issue? Thanks in advance.
 
I'm sure other would chime in, but I would have someone else drive the boat. When it happens, check the bulb. Is it tucked flat? Squeeze it, is it firm?

Could be a vent issue. Could be the bulb, Could be the vst. All are pretty easy fixes.

Does each motor draw from its own fuel tank? If so, you could also hook up a small portable fuel tank. If it runs fine, you know the issue is fuel.

My guess, and starring point would be vst. Very easy to clean. If u don't have an Honda service manual, get one for your motor.
 
There is a fine screen below the hp pump that commonly gets clogged. You need to open the VST and remove the hp pump to find it. They are difficult to remove without damaging, so maybe order one
 
The filter screen lock inside the VST has three black tabs that hold it to the fuel pump. its hard to keep all three tabs open at same time to remove the pump from the screen. What I do is slide black zip ties down each holding tab on the side of the fuel pump which keeps them open and wiggle the pump a little bit and the pump usually comes out without a lot of brute force ruining the screen holder.
 
It sounds like the engine is getting starved for fuel. it runs a bit then runs out of fuel then at idle it catches back up and runs a bit more. I had mercury 150 do exact same thing with 52 hours on it and it was fuel filter in the engine had clogged. Likely from shavings from tank manufacture as there was no fuel water sep on this relatively new boat. did you replace the filters before or after this started to occur?
Check fuel water seprator oring on the boat. put grease on it and tighten by hand til snug.
its possible the engine fuel water Seperator or low pressure filter has a o rings have a flat spot and is not getting a seal. takeout inspect and grease those cup o rings. The Oring on the high pressure filter cover has to be replaced it is not reusable, they stretch or flat spot easily.
Could be fuel tank vent or clamp connection on primer bulb not tight enough.
 
Ty all, i replaced the bulb so far. The water fuel seperator look new. The low pressure filter looks new. Both have been replaced last year. This occured after the change on 1 of the motors, the port runs great.
Question: should the bulb allow air out both ways? One way valve i thought wouldnt let any air back words
 
Bustedknuckle said:
Ty all, i replaced the bulb so far. The water fuel seperator look new. The low pressure filter looks new. Both have been replaced last year. This occured after the change on 1 of the motors, the port runs great.
Question: should the bulb allow air out both ways? One way valve i thought wouldnt let any air back words
Click to expand...

If this happened after you changed a filter, I'd say it's sucking air somewhere....
 
I think you need to take the guesswork out. Get or borrow a fuel pressure gauge and monitor the pressure. It shouldn't drop below 42 psi under load. You may be chasing the wrong issue.
 
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