Hey all,
First time posting here, but I don’t know where else to turn. I’ve been having some very odd issues with my 2020 60HP Mercury EFI Outboard. Bought the motor for a boat I restored a few months back. When I first starting running the motor, it ran pretty well, but occasionally would hesitate at high speeds/RPMs. This issue would occur off and on until recently it became so bad that the motor would consistently lose power over a certain RPM and refuse to accelerate any more. I suspected a fuel supply issue so replaced both fuel filters. No improvement. My next step was to replace the low pressure mechanical fuel pump and the high pressure electrical fuel pump in the VST. I also checked the VST for other issues while in there, and everything (screens, etc.) looked good. I put the new pumps in and took it for a test drive. Seemed to run well but then when I tried to accelerate, again it hesitated and this time an alarm bell sounded once. This would also sound any time I tried to raise the RPMs above a certain level. Eventually limping back, I could barely raise the throttle at all without a beep from the engine. I got back and eventually hooked up a fuel pressure gauge to the port and took it out again: this time the hesitation seemed to lessen, and the fuel pressure maintained around 42-47 PSI according to the gauge, even under load at speed, but again I could barely accelerate without the alarm sounding. I’m at a total loss now of what the issue is. Other weird occurrence: after replacing the 2 fuel pumps, I definitely am noticing a modest amount of fuel coming out of the lower unit at rest. But after inspecting the motor and the lines/connections, I can’t see any leaking, even under throttle.
Any help would be appreciated!
First time posting here, but I don’t know where else to turn. I’ve been having some very odd issues with my 2020 60HP Mercury EFI Outboard. Bought the motor for a boat I restored a few months back. When I first starting running the motor, it ran pretty well, but occasionally would hesitate at high speeds/RPMs. This issue would occur off and on until recently it became so bad that the motor would consistently lose power over a certain RPM and refuse to accelerate any more. I suspected a fuel supply issue so replaced both fuel filters. No improvement. My next step was to replace the low pressure mechanical fuel pump and the high pressure electrical fuel pump in the VST. I also checked the VST for other issues while in there, and everything (screens, etc.) looked good. I put the new pumps in and took it for a test drive. Seemed to run well but then when I tried to accelerate, again it hesitated and this time an alarm bell sounded once. This would also sound any time I tried to raise the RPMs above a certain level. Eventually limping back, I could barely raise the throttle at all without a beep from the engine. I got back and eventually hooked up a fuel pressure gauge to the port and took it out again: this time the hesitation seemed to lessen, and the fuel pressure maintained around 42-47 PSI according to the gauge, even under load at speed, but again I could barely accelerate without the alarm sounding. I’m at a total loss now of what the issue is. Other weird occurrence: after replacing the 2 fuel pumps, I definitely am noticing a modest amount of fuel coming out of the lower unit at rest. But after inspecting the motor and the lines/connections, I can’t see any leaking, even under throttle.
Any help would be appreciated!
