Hello,
I have a 1988 Bayliner with an OMC 3.0, 4 cyliner motor. I am working through troubleshooting an issue where the motor runs fine for about 25 minutes and then starts to struggle, and run very poorly.
I have only owned this boat for less than a year and do not know the history.
So far in working through this issue, I have gone through the fuel system, replaced the fuel filter and the water seperator. I checked all the fuel lines and replaced the carb with a rebuild. I removed the little anti syphion valve at the fuel tank and pulled the fuel sending unit out of the tank, pumped about 3 gallons of fuel off the bottom of the tank and let it settle into a clear glass. I do not see any fuel contamination. I also ran the boat on a 5 gallon clean tank with fresh fuel and the issue is still there. I am pretty certian that it is not a fuel issue.
I have replaced the spark plugs, the plug wires, the dist. cap, rotor, condensor, and points. I set the point gap as recited in the seloc manual and rechecked them. I belive i am correct. However, this issue is just the same before and after I did the "tune up".
I am now doing testing with my meter and at the + side of the coil, I have right around 12v with the key in the run position, points open. with the boat running, I have about the same. It is my understanding that with the boat running, the voltage should be less than 12V at the positive side of the coil? I tested the resistance wire by unhooking it at the key and coil and it was 3.9 oms. Then if I plug the wire into the key switch and test from the open end at the coil with the key in run position, I am getting 11.8 volts, engine not running.
I checked the key switch, it seems to be doing as it should, the start and the run are not "bridging" or anything. I also disconnected the wire that comes from the start side to the positive side to make sure it was not live when in the run position and it is functioning as it should but still 12 volts at the coil in the run position.
I do intend to do a compression test but waiting on equipment.
Is there something I am missing, is there any other tests I should be doing? is chasing this coil thing a red herring?
Thank You in advance
I have a 1988 Bayliner with an OMC 3.0, 4 cyliner motor. I am working through troubleshooting an issue where the motor runs fine for about 25 minutes and then starts to struggle, and run very poorly.
I have only owned this boat for less than a year and do not know the history.
So far in working through this issue, I have gone through the fuel system, replaced the fuel filter and the water seperator. I checked all the fuel lines and replaced the carb with a rebuild. I removed the little anti syphion valve at the fuel tank and pulled the fuel sending unit out of the tank, pumped about 3 gallons of fuel off the bottom of the tank and let it settle into a clear glass. I do not see any fuel contamination. I also ran the boat on a 5 gallon clean tank with fresh fuel and the issue is still there. I am pretty certian that it is not a fuel issue.
I have replaced the spark plugs, the plug wires, the dist. cap, rotor, condensor, and points. I set the point gap as recited in the seloc manual and rechecked them. I belive i am correct. However, this issue is just the same before and after I did the "tune up".
I am now doing testing with my meter and at the + side of the coil, I have right around 12v with the key in the run position, points open. with the boat running, I have about the same. It is my understanding that with the boat running, the voltage should be less than 12V at the positive side of the coil? I tested the resistance wire by unhooking it at the key and coil and it was 3.9 oms. Then if I plug the wire into the key switch and test from the open end at the coil with the key in run position, I am getting 11.8 volts, engine not running.
I checked the key switch, it seems to be doing as it should, the start and the run are not "bridging" or anything. I also disconnected the wire that comes from the start side to the positive side to make sure it was not live when in the run position and it is functioning as it should but still 12 volts at the coil in the run position.
I do intend to do a compression test but waiting on equipment.
Is there something I am missing, is there any other tests I should be doing? is chasing this coil thing a red herring?
Thank You in advance