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Honda BF60A Fuel Pressure Issue **Please Help**

J

JLM1979

New member
I have a Honda BF60A outboard. The motor runs fine when not under load (in water) but once under load in water it stalls out. I checked the fuel pressure and it was low ~35 PSI pointing to the fuel pressure regulator. So I installed a new regulator. After installing the regulator I retested. With the vacuum line attached I got the same. When the vacuum was removed it went up to 43 PSI. I am at a loss. Someone please help!
 
Hi,
I haven't worked on one of these nor do I have the service info (shop manual) for one.
But, from what I've seen reading posts here and on other sites, your fuel pressure sounds like it may be ok.....41 to 43 psi vacuum line removed from FPR and 35 psi vacuum line attached with engine at idle.

Engine vacuum is used to LOWER the fuel pressure at idle to prevent engine flooding.

Also, there is a Technical Service Bulletin (TSB) for many of these engines regarding low power being caused by a faulty fuel pump "insulator".grommet.
See item 28 in the parts link below:


That grommet is actually pretty famous for causing low power complaints on the Honda 60.

It can be easily mis-installed and it seems that many original ones weren't made correctly.

I've read about people cutting the top of the grommet to improve the issue.

When replacing the grommet it should be installed on the pump prior to installing the pump into the VST case.

Apparently, if the grommet is installed into the VST and then the pump is pushed up into the grommet, it's very easy to "wad up" the small end of the grommet and restrict fuel flow.

That can cause low power and isn't good for the pump either.

Like I said, no experience with these....just sharing what I've read.

Hopefully someone else here that has dealt with this will chime in with their knowledge.

Good luck.
 
Jimmy's spot on, your fuel pressure is normal as he described. Do your usual compression test, cylinder drop test, if good, check grommet on the high pressure pump
 
I took off the VSP and cleaned everything and inspected the grommet. It looked fine. I was not deformed or damaged from what I could see. I have the tech manual for the outboard and Honda says the standard pressure should be around 40 PSI with the vacuum line attached to the regulator and around 48 when not. I don't get that it drops to 35 when attached and goes to 41 when detached. I am stuck. I am not sure why my pressure is not reading to spec. I want to water test under load but don't feel like being towed to the dock again.
 
I also test the compression of the motor and that was fine. Would an O2 sensor cause fuel pressure issues? I checked the ohms of the heater side of the O2 sensor and it was low and out of spec.
 
Okay, let me explain, virtually all EFI systems have a vacuum connecon to the regulator. The purpose of this is to pull the fuel pressure down at idle when the manifold vacuum is at its greatest.So when doing a test you pull the hose off to check you're getting full pressure when there is no vacuum,ie wide open throttle. The top hat shaped grommet often shows no sign of restricting fuel flow, even so, they do get compressed when installed and will restrict fuel flow. I make it a general practice to slice the top off completely and then reinstall. If you want to confirm this condition, the only way is to run the motor under full power with your pressure gauge attached, until the motor dies and see what happens to the fuel pressure. You can do this by tying the boat up securely to a strong dock, that way you needn't wory about getting stranded. The )2 sensor will not cause this issue, try what I have just described and let me know the results. Judgeing by your description I am pretty certain this is a fuel related problem
 
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