Oil pooling in 70 hp bottom carb

[pigflipper]

We have a 1993 70 hp engine that we have been struggling with low power at WOT. Sometimes we jump up on plane without an issue and maintain power as long as we stay at WOT. Other time the engine bogs down before getting on plane. Repeated attempts to get back on plane by going down to idle then back to WOT will eventually get us going again. We have cleaned carbs in the past and since replaced the entire fuel system including tank, fuel pump, and all lines on and off of the engine. We decided to clean and rebuild carbs again. I have the Yamaha repair manual and have purchased the carb repair kits. When I pulled the silencer off the first thing I saw was oil filling the throat of the bottom carb and some oil standing in the middle carb.

Is the oil in the carb related to our power loss problem and what would be the possible cause?

Thanks,
pigflipper

[boats.net]

You will have small amout od oil puddle if motor is tilted up some after shutting engine off, check oil line check valves are working correctly, check engine reed valves to see if broken, run a compression test on engine.