I have twin 2006 BF150s. I've noticed that I have to push the throttle further on my starboard (standard-rotation) engine more to reach the same RPM as the port (counter-rotation) engine. The starboard/S-R engine also appears to consume more fuel that the port/C-R engine, which seems strange because as I understand it, the C-R engine usually consumes more fuel. My starboard engine also runs 10-20 degrees cooler than the port engine. While the temperature difference could be related to cooling issues (I plan to clean the little passages in the block as thoroughly as I can next spring), I have done vinegar flushes and salt-away flushes in both engines and put new impellers in last fall, and I'm pretty religious about flushing them after each use.
Attached are two screenshots from my displays. The temperatures are being read from the ECT4 sensor and were calibrated using an ODB tool as well as an IR gun. The fuel consumption figures are based on signals from the ECMs, which were very accurate earlier this season (within 1%). Caveat: because I troll a lot and alternate engines, and my electronics only track total fuel consumed for both engines combined, I haven't been able to verify the consumption per engine recently when fueling up. It might be possible that dirty injectors or some other 'new' flow issue on the starboard side is resulting in less actual flow than the ECM is reporting.
Also, while the port/C-R engine increases in RPM smoothly, the starboard/S-R one seems to get "stuck" in the low-4000's. It will then "jump" into the mid/high-4000's, at which point I gently back it down to my preferred cruising RPM of ~4,500. This phenomenon occurs most frequently when I'm starting out on trips (after a ~5-minute warm-up period), and then seems to get better after cruising for a while.
The throttle position & fuel consumption difference seems to be getting worse recently; any thoughts as to what might cause it and how to troubleshoot?
Attached are two screenshots from my displays. The temperatures are being read from the ECT4 sensor and were calibrated using an ODB tool as well as an IR gun. The fuel consumption figures are based on signals from the ECMs, which were very accurate earlier this season (within 1%). Caveat: because I troll a lot and alternate engines, and my electronics only track total fuel consumed for both engines combined, I haven't been able to verify the consumption per engine recently when fueling up. It might be possible that dirty injectors or some other 'new' flow issue on the starboard side is resulting in less actual flow than the ECM is reporting.
Also, while the port/C-R engine increases in RPM smoothly, the starboard/S-R one seems to get "stuck" in the low-4000's. It will then "jump" into the mid/high-4000's, at which point I gently back it down to my preferred cruising RPM of ~4,500. This phenomenon occurs most frequently when I'm starting out on trips (after a ~5-minute warm-up period), and then seems to get better after cruising for a while.
The throttle position & fuel consumption difference seems to be getting worse recently; any thoughts as to what might cause it and how to troubleshoot?