Hello, we have a 1999 Maxum with Mercruiser 5.7 (with carb) and Alpha one Gen II that developed a new stalling issue over the past few weeks. I appears to be increasing in frequency as in now at 4+ stalls per trip.
The issue occurs after running the boat for 15+ minutes at higher RPMs, then when coming off plane it generally occurs at 1000-1500rpm. But it has happened a few time at 4000rpm and also at idle. Upon testing at idle we were able to replicate the problem once after quickly turning the stereo and all the lights,bilge, blower switches on at once to create an electrical load. Perhaps this behavior could point to an electrical problem?
So far we have changed out the water fuel separator (which had no water in it) and put new fuel in the boat, but we don't suspect it being a fuel issue as the engine runs smooth all all RPMS with no sputtering. It starts right up normally and even after it stalls. In general the boats engine sounds and performs great. When the does boat stall out, it is very abrupt and I would assume if it was a fuel issue there would be some seconds of fuel to burn through in the carb.
There was some out-drive work done in the off season, but we don't suspect the shift cable interrupter switch as this issue occurs in neutral or forward at various rpms and NOT while shifting.
When the boat was purchased a few months back the main power cables to the batteries and the battery switch were badly corroded, we cleaned them with a wire brush and replaced one. The red battery 1 and 2 and off switch is really hard to turn between options as well.
Also the voltmeter on the dash isn't working at all. This is on the list of items to replace already
When we use the handheld voltmeter in the cigarette lighter socket we get 12.8V when the boat is off and 14.4 when running. Which seem really normal.
The tachometer is not working properly and bounces around for bit until it finally gets to what seems is the accurate RPMs. Could the tachometer actually CAUSE an electrical problem or short? I thought it was just a sensor. This is on the list of items to replace already.
What should we try next to help troubleshoot this issue?
I have read it could be the:
-Fuel anti siphon valve? (but I doubt that since the stalling is so abrupt)
-Main wire from the coil to the distributor
-A shorted gray tachometer wire or tachometer?
-engine electrical harness or key switch?
Thanks!!
The issue occurs after running the boat for 15+ minutes at higher RPMs, then when coming off plane it generally occurs at 1000-1500rpm. But it has happened a few time at 4000rpm and also at idle. Upon testing at idle we were able to replicate the problem once after quickly turning the stereo and all the lights,bilge, blower switches on at once to create an electrical load. Perhaps this behavior could point to an electrical problem?
So far we have changed out the water fuel separator (which had no water in it) and put new fuel in the boat, but we don't suspect it being a fuel issue as the engine runs smooth all all RPMS with no sputtering. It starts right up normally and even after it stalls. In general the boats engine sounds and performs great. When the does boat stall out, it is very abrupt and I would assume if it was a fuel issue there would be some seconds of fuel to burn through in the carb.
There was some out-drive work done in the off season, but we don't suspect the shift cable interrupter switch as this issue occurs in neutral or forward at various rpms and NOT while shifting.
When the boat was purchased a few months back the main power cables to the batteries and the battery switch were badly corroded, we cleaned them with a wire brush and replaced one. The red battery 1 and 2 and off switch is really hard to turn between options as well.
Also the voltmeter on the dash isn't working at all. This is on the list of items to replace already
When we use the handheld voltmeter in the cigarette lighter socket we get 12.8V when the boat is off and 14.4 when running. Which seem really normal.
The tachometer is not working properly and bounces around for bit until it finally gets to what seems is the accurate RPMs. Could the tachometer actually CAUSE an electrical problem or short? I thought it was just a sensor. This is on the list of items to replace already.
What should we try next to help troubleshoot this issue?
I have read it could be the:
-Fuel anti siphon valve? (but I doubt that since the stalling is so abrupt)
-Main wire from the coil to the distributor
-A shorted gray tachometer wire or tachometer?
-engine electrical harness or key switch?
Thanks!!
