RE: Honda BF 90-D. I just had annual service done on my twin 90s at a reputable shop. Service included removal of gear case to replace impeller. When i put boat back in water and started engines, the port engine was much louder and there is a large effusion of bubbles coming up on both sides of the lower unit casting. It looks like this bubbling originates in the area of the anodes, which were also both replaced. I would post a video but cannot figure out how to do so. Can anyone venture a site unseen guess as to the problem ?
I am no mechanic but in the service manual it looks like the anode location penetrates clear into the inside of lower unit casting and would therefore be hydraulically (pneumatically?) connected to the exhaust port that is behind the water pump. Are there supposed to be seals on the anodes to prevent exhaust discharge ? I don't know for sure that is where the exhaust is exiting but I have good sized perma-trim foils on the motors that bolt to the anti-ventilation plate, and the exhaust is definitely above the foils. I suppose another possibility is the mechanic failed to notice some debris on the casting mating surface when he bolted lower unit back on, and exhaust is just escaping at this joint.
I am no mechanic but in the service manual it looks like the anode location penetrates clear into the inside of lower unit casting and would therefore be hydraulically (pneumatically?) connected to the exhaust port that is behind the water pump. Are there supposed to be seals on the anodes to prevent exhaust discharge ? I don't know for sure that is where the exhaust is exiting but I have good sized perma-trim foils on the motors that bolt to the anti-ventilation plate, and the exhaust is definitely above the foils. I suppose another possibility is the mechanic failed to notice some debris on the casting mating surface when he bolted lower unit back on, and exhaust is just escaping at this joint.