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Honda bf60 EFI fuel issues

Jonnybravo

New member
Ok guys need some diagnostic help. We have a 21ft aluminum hull with 2 Honda bf60's. It has rough idle and will intermittently stop revving at 2000rpm while at full throttle. When brought back to neutral will occasionally stall and have a hard time starting. We have swapped fuel tanks, new fuel filter, new high pressure fuel filter, new fuel lines. Any help would be appreciated.
 
If I am understanding correctly....if you are at full throttle (I assume close to 6000 rpm), the motor will drop down to about 2000 rpm and will occasionally completely stall. Then you have a hard time starting.

Does it always start good when cold?

When the engine is failing, have you tried having someone squeeze the fuel bulb to keep it hard?

If the answer is yes to both questions, then my next step would be to check the fuel pressure at the vapor separator. There is a small bolt to remove on the vapor separator to attach a pressure gauge.

Unfortunately, you have to get it to fail, then see what the fuel pressure is doing. It should be around 40 psi or a little above when under way.

If the fuel pressure reduces to 20 psi or close to zero and the motor will still not restart, then make sure the squeeze bulb is hard and have a helper turn the key switch to on, while you listen to hear if the high pressure fuel pump is running for 2 seconds. If it is and there is little fuel pressure, then drain the vapor separator to see if there is fuel in it.

If the pump is running and there is little pressure and there is fuel in the vapor separator, I would check three things...two involves removing the vapor separator and the high pressure pump.
1. Check the pressure regulator by pinching off the regular control tube and see if pressure goes up....it should....but if it does not, the regulator still may be good.
2. Check to see if the screen under the pump is clogged with debris.
3. Remove the grommet that the pump is inserted into. Part #28 http://www.boats.net/parts/search/H...Later/BF60AK1 LRTA/VAPOR SEPARATOR/parts.html

If you look into the opening that the grommet is in, there is a very small opening for the fuel to go out. It is possible that the grommet end is smashed and expended to the point to close over that hole...once the engine warms up and fuel flows through it. If you look at the grommet, you may see an imprint of the opening on the grommet. This is a sign that you may have just found the problem. While it is out....slice about 1/16" off the end of the grommet that goes into the opening. That will give it more space for the fuel to flow out of the opening.

That all may be all out in left field. If the grommet is the problem, that will not necessarily fix the idle problem.

Mike
 
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