I have a volvo penta DPA powered by a 431a engine. Went to get up on the plane and all seems fine untill I hit 3000 rpm and its like its a spun prop and lets go. The engine revs out and the boat goes nowhere. It goes into gear fine and runs along fine under 3000rpm. As soon as I hit 3000 it just revs out. Took the props off to check but I have solid aluminium props so no facility for them to fail. Can anyone point me in the right direction of where the problem is. It doesn't feel like the cone clutch as I have had one of those fail before. From my experience when one of those fails it revs up slightly hire from idle before it engages into gear with a clunk.
