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Yamaha 300 HDPI cooling

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omegahart

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Anyone know how much water should come out of the square exhaust ports on a 300 hp HPDI Yamahas. Both have good streams from the holes but the left engine spits a lot of water from the exhaust port while the other barely spits any.
 
There are no temp guages. Will bring a thermal gun out on Sunday to see. Will try to idle up the engine I am concerned about to see if it helps.
 
Got out on Sunday. While setting the anchor, I got in the water to see the exhaust ports. Brought up the RPM on the starboard engine and it began to spit the same amount of water through the exhaust as the port. Could the counter rotation of the props starve one engine for water? When shut off engines, the starboard had some smoke drifting out of the exhaust port and some smoke drifted out out from under the cowl. Trimmed up and had a lot of water come out of the starboard from below the cowl but none from port. Is there a gasket or seal that could be leaking?
 
sounds like both are working right, did you take any temp reading?
as far as trimmed up and the water leaking from below the cowling, was it coming from the exhaust holes or from where, water will drain from the motors when they are trimmed up or removed from the water.
 
I forgot to bring my handheld temp gun. Will check next time. The water was not coming from the exhaust port or visual pee spot. When you remove the cowel, there is a lower fiberglass piece. The water came from between the lower edge of the fiberglass on the right side facing the back of the motor where the lower unit slides into the fiberglass cowel. I will get a photo.
 
Both motors are running between 130 and 140 degrees. On last trip out the starboard engine would occasionally lose some power then regain. Could really feel the power loss and power up. Found that both the water fuel separator filters were Mercury 20 micron filters. Changed both to proper Yamaha filters and cleaned the canister filters on each motor. Having trouble with getting the port motor filter seal to set. Starts a small leak around the threads when the fuel pump turn on. Starboard filter is not leaking. Starboard motor still bogs down. Any trick to the filter or suggestions on the power loss? I assume 130 to 140 degree temperature is within proper range.
 
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