2012 Mercury 225L Optimax
225hp
Model# 1225D73EY
Serial# 1B918114
Mercury Tempest Plus Elite 25P
Standard Gearcase
WOT....54MPH @ 5000rpm
P2P distance....4"
Hey guys. I have an issue somewhere in my boat. The previous owner had the boat at 65 MPH @ 5800rpm. I've barely been able to get the boat up to 51mph @ 5000rpms WOT. The only thing that's different with the boat now from the previous owner is the prop to pad distance. He was running it at 4.5" and I highered the jackplate 1/2in to bring the P2P to 4". I'm getting cavitation at 4000 and shooting up to 6000 then dropping back to 5000rpms where it will stay and and run smoothly once fully on plane. I was convinced the engine was running great because it had perfect compression but after studying more and learning that perfect compression doesn't mean perfect cylinders, plugs, plug wires, or fuel injectors, the next thing that made very good sense was a bad coil since the spark plugs and wires are brand new. I purchased an inline spark tester and went to work in the driveway thinking I was going to find a bad coil somewhere for sure. Turns out all 6 are giving perfect spark. I then tried the other method of unplugging each cylinder while the engine was running. They all reacted the same way except for the #5 cylinder. When I unplugged that one the engine didn't bog down as much as when I unplugged the others. Also when I plugged the others back in there was a clear sign of the engine regaining power. There was no sign of power regain at all when plugging #5 back in. I also got a 3 beep alarm if it was unplugged for more than a few seconds or so. There were no alarms at all when any of the others were unplugged or when the boat was running normally. I know this tells me something. I just don't know what. I'm hoping that somebody knows where I should go from this point. Could the #5 fuel injector be bad? PLEASE HELP!!
225hp
Model# 1225D73EY
Serial# 1B918114
Mercury Tempest Plus Elite 25P
Standard Gearcase
WOT....54MPH @ 5000rpm
P2P distance....4"
Hey guys. I have an issue somewhere in my boat. The previous owner had the boat at 65 MPH @ 5800rpm. I've barely been able to get the boat up to 51mph @ 5000rpms WOT. The only thing that's different with the boat now from the previous owner is the prop to pad distance. He was running it at 4.5" and I highered the jackplate 1/2in to bring the P2P to 4". I'm getting cavitation at 4000 and shooting up to 6000 then dropping back to 5000rpms where it will stay and and run smoothly once fully on plane. I was convinced the engine was running great because it had perfect compression but after studying more and learning that perfect compression doesn't mean perfect cylinders, plugs, plug wires, or fuel injectors, the next thing that made very good sense was a bad coil since the spark plugs and wires are brand new. I purchased an inline spark tester and went to work in the driveway thinking I was going to find a bad coil somewhere for sure. Turns out all 6 are giving perfect spark. I then tried the other method of unplugging each cylinder while the engine was running. They all reacted the same way except for the #5 cylinder. When I unplugged that one the engine didn't bog down as much as when I unplugged the others. Also when I plugged the others back in there was a clear sign of the engine regaining power. There was no sign of power regain at all when plugging #5 back in. I also got a 3 beep alarm if it was unplugged for more than a few seconds or so. There were no alarms at all when any of the others were unplugged or when the boat was running normally. I know this tells me something. I just don't know what. I'm hoping that somebody knows where I should go from this point. Could the #5 fuel injector be bad? PLEASE HELP!!