Well all last week my marine mechanic had my boat. He got 2 opinons on the knocking and said it was some kind of valve in the steering mechanism that was worn and making knocking noises. One was on order and he told me I could use the boat with no ill effect until.....
The boat suffered some kind of u-joint/drive failure yesterday on the lake
I stopped to help a boater whose boat died in the water, ironically it was a Vista 238 with the same engine/duo-prop as me, his fuel pump went out..anyways, I went to turn around, was idling over to him and BANG BANG BANG BANG....boat stalled. Thank god I was idling, the u-joint must've let loose. I was very happy I bought West Marines unlimited towing package, I got back to port for FREE, would've cost me $555. Anyway, I will keep the board updated. Mechanic is coming out tomorrow.
In the mean while, who has replaced their u-joints on their duo-prop outdrive before and what part # did you use??
not to mention there was water intrusion as well. Strange, because it never made it to my bilge. I checked continuously after the "big bang" but there certainly was some in the bellows. 
