Looking for a little more advance direction.
we recently purchased the motor with a rebuilt powerhead.
This is a 2+2 motor where the top two cylinders run and the bottom two kick in around 1800 rpm. we knew there would be some bugs to work out upon purchasing the motor and are trying to get the motor dialed in.
For the fuel system I have run new lines and installed the larger and smaller filters and inspected the accelerator pump and it has tested fine. I have disassembled the carbs and they were clean from the rebuild and reassembled. the idle screws on the top two carbs were set to factory spec turned out 1 1/2 turns. the fuel system seems to be in good shape.
The ignition system I am a little more unsure of. We recently discovered going through the Mercury service manual that the stator isn't of the wiring configuration in the mercury manual. The mercury stator in the manual is a 6 wire- two yellow, a blue and blue/white, and a red and a red/white. The one on the motor resembles a Mallory or Seirra configuration with what looks like an in line voltage regulator with only two wires to connect to the switch box- a blue and a blue /white. I have new plugs and have tested the spark with an in line spark plug tester and have spark on all 4 cylinders. The boat starts up and idles fine and when you hit the throttle you can tell the bottom cylinders are kicking in and it then seems to fall on its face and doesn't get past 3600 rpm. I am able to squeeze the primer bulb as I am driving but the forced squeezing seems to make the motor fall off slightly rather than pick it up. I did stumble on one thing that allowed the rpms to climb quickly. the one tank was low on fuel and wasn't able to draw all the fuel it would normally through the gas line and the motor climbed quickly to between 4500 and 5000 rpms then stopped running. I then had to switch tanks and was unable to replicate that exact senario. I then was able to somewhat replicate it by running the boat at idle the quickly disconnecting the fuel line from the motor and accelerate to full throttle and it would go to 4100 rpm the then stop running.
Other notes
We have oil mixed in with the gas in the tank for break in and the engine is oil injected. From the best of our knowledge the stator is new and we know the switchbox is new.
I am between the idea that the issue is between the fuel system or the ignition system. It seems like either the motor is getting too much fuel , or the spark is to weak for combustion at the higher speed. could it be from the additional oil in the fuel? Could anyone help shed some light on what can be done to resolve the motor not finding the other 2000 rpms it is capable of with out running out of gas? Any help would be appreciated. Also any thoughts on the aftermarket stator with the two low speed wires? Thanks Glenn
we recently purchased the motor with a rebuilt powerhead.
This is a 2+2 motor where the top two cylinders run and the bottom two kick in around 1800 rpm. we knew there would be some bugs to work out upon purchasing the motor and are trying to get the motor dialed in.
For the fuel system I have run new lines and installed the larger and smaller filters and inspected the accelerator pump and it has tested fine. I have disassembled the carbs and they were clean from the rebuild and reassembled. the idle screws on the top two carbs were set to factory spec turned out 1 1/2 turns. the fuel system seems to be in good shape.
The ignition system I am a little more unsure of. We recently discovered going through the Mercury service manual that the stator isn't of the wiring configuration in the mercury manual. The mercury stator in the manual is a 6 wire- two yellow, a blue and blue/white, and a red and a red/white. The one on the motor resembles a Mallory or Seirra configuration with what looks like an in line voltage regulator with only two wires to connect to the switch box- a blue and a blue /white. I have new plugs and have tested the spark with an in line spark plug tester and have spark on all 4 cylinders. The boat starts up and idles fine and when you hit the throttle you can tell the bottom cylinders are kicking in and it then seems to fall on its face and doesn't get past 3600 rpm. I am able to squeeze the primer bulb as I am driving but the forced squeezing seems to make the motor fall off slightly rather than pick it up. I did stumble on one thing that allowed the rpms to climb quickly. the one tank was low on fuel and wasn't able to draw all the fuel it would normally through the gas line and the motor climbed quickly to between 4500 and 5000 rpms then stopped running. I then had to switch tanks and was unable to replicate that exact senario. I then was able to somewhat replicate it by running the boat at idle the quickly disconnecting the fuel line from the motor and accelerate to full throttle and it would go to 4100 rpm the then stop running.
Other notes
We have oil mixed in with the gas in the tank for break in and the engine is oil injected. From the best of our knowledge the stator is new and we know the switchbox is new.
I am between the idea that the issue is between the fuel system or the ignition system. It seems like either the motor is getting too much fuel , or the spark is to weak for combustion at the higher speed. could it be from the additional oil in the fuel? Could anyone help shed some light on what can be done to resolve the motor not finding the other 2000 rpms it is capable of with out running out of gas? Any help would be appreciated. Also any thoughts on the aftermarket stator with the two low speed wires? Thanks Glenn