Motor is a 1999 Mercury EFI 225 on a 1990 Mako 230.
Symptoms
This spring, I replaced the fuel tank, along with the fill and vent lines. I also replaced the line to the first filter. Currently the boat is set up Tank>30micron filter>Garmin GFS 10>Racor 10 micron water/fuel separator>fuel bulb>motor water/fuel separator.
Last weekend I launched and noticed some hiccups, chugs etc at lower RPM. Yesterday, I replaced all 3 fuel filters ? the one ahead of the Garmin I did not know about until this spring when the Tank was replaced, and I did not have a replacement until yesterday. Ran the boat, and things seemed much better, no chugging and minimal bogging.
Today, I ran the boat with a remote 6 gallon tank with a heavy dose of Seafoam. I set up the tank with the fuel line from the Racor to the motor bypassing the Racor, garmin sensor, and 30 micron filter. Afterwards, the bogging and chugging got worse. No discernable difference between the remote tank and the boat tank.
The good news is that at idle in neutral, the motor is smooth, and at 4000-4800 it is also smooth. I did notice some erratic readings from the Garmin sensor after replacing the filter, which seemed to settle down after some fuel ran through the motor, I?m assuming this was caused by bubbles, but there could be some crud in the sensor, given the age of the filter ahead of it. I also have seen slightly better fuel economy at 4000 RPM which is nice. Was consistently above 1.7 and saw up to 2.2 which I?d be quite happy with.
Today, after the Seafoam remote tank, when the motor is running at 4000 RPM, the boat is at 30kts. Jumping up to 4800 only gained about 4 kts. Boat will not run at medium rpms ? jumps from 1800 to 4000 RPM, on way down, boat can hold some throttle levels in medium RPM range.
Spark plugs were new last year.
Some history.
Boat was new to me last year, the PO only had it a year, the Prior PO had the boat for 10 plus years. Last year, I experienced some issues with low WOT (approx. 5000) and found at one point that one cylinder was not firing as the wiring harness was unplugged. When harness reattached, boat got up to 5600 RPM.
Experienced ventilation issues last year, resulting in my buying a new Stainless Mirage Plus 15x17 propeller. Prior to that, boat had a 19? pitch prop which was on when the boat got up to 5600 RPM. The prop solved ventilation issues.
As year went on, performance degraded, loss of WOT and speed. I attributed it to bottom growth after pulling the boat and finding barnacles and such on the hull. However, I had measured high fuel pressure (47lbs) and pulled the filter by the fuel pump and checked the little screen which was clean.
Symptoms
- WOT only at 48-4900 RPM
- Idles at 1200 out of gear, ~800 in gear
- Chugs and bogs at RPM up to 2000
- Takes 3 or 4 times then will jump from 2000 to 4000 RPM
This spring, I replaced the fuel tank, along with the fill and vent lines. I also replaced the line to the first filter. Currently the boat is set up Tank>30micron filter>Garmin GFS 10>Racor 10 micron water/fuel separator>fuel bulb>motor water/fuel separator.
Last weekend I launched and noticed some hiccups, chugs etc at lower RPM. Yesterday, I replaced all 3 fuel filters ? the one ahead of the Garmin I did not know about until this spring when the Tank was replaced, and I did not have a replacement until yesterday. Ran the boat, and things seemed much better, no chugging and minimal bogging.
Today, I ran the boat with a remote 6 gallon tank with a heavy dose of Seafoam. I set up the tank with the fuel line from the Racor to the motor bypassing the Racor, garmin sensor, and 30 micron filter. Afterwards, the bogging and chugging got worse. No discernable difference between the remote tank and the boat tank.
The good news is that at idle in neutral, the motor is smooth, and at 4000-4800 it is also smooth. I did notice some erratic readings from the Garmin sensor after replacing the filter, which seemed to settle down after some fuel ran through the motor, I?m assuming this was caused by bubbles, but there could be some crud in the sensor, given the age of the filter ahead of it. I also have seen slightly better fuel economy at 4000 RPM which is nice. Was consistently above 1.7 and saw up to 2.2 which I?d be quite happy with.
Today, after the Seafoam remote tank, when the motor is running at 4000 RPM, the boat is at 30kts. Jumping up to 4800 only gained about 4 kts. Boat will not run at medium rpms ? jumps from 1800 to 4000 RPM, on way down, boat can hold some throttle levels in medium RPM range.
Spark plugs were new last year.
Some history.
Boat was new to me last year, the PO only had it a year, the Prior PO had the boat for 10 plus years. Last year, I experienced some issues with low WOT (approx. 5000) and found at one point that one cylinder was not firing as the wiring harness was unplugged. When harness reattached, boat got up to 5600 RPM.
Experienced ventilation issues last year, resulting in my buying a new Stainless Mirage Plus 15x17 propeller. Prior to that, boat had a 19? pitch prop which was on when the boat got up to 5600 RPM. The prop solved ventilation issues.
As year went on, performance degraded, loss of WOT and speed. I attributed it to bottom growth after pulling the boat and finding barnacles and such on the hull. However, I had measured high fuel pressure (47lbs) and pulled the filter by the fuel pump and checked the little screen which was clean.