Merc 3.0L V6 dual water pick lower unit.

[mac90sup]

Has anyone ever completely blocked off the side water pickups on the Merc 3.0L dual water pick up gearcase, thus allowing only the water pick ups in the nose cone to feed the impeller. (I know fully well that bobs nose cone or a sportmaster is the way to go)Just exploring all my options. I already have the Merc side water pick up scoops. These have increased water pressure at speed substantially but I still am losing water pressure when I trim the motor out and/or the boat speed increases. This is triple engine application and the center motor is the one where the water pressure is dropping off as the boat speed increases and/or the motors are trimmed out. Worth noting,the Outside motors have good pressure consistently. I Feel like air is getting in the side pick ups and aerating the impeller. Any input or advise would be appreciated. Worth noting, this boat initially had lower units with bobs machine nose cones installed. Thanks guys

[gotboostedvr6]

Good question.

[mac90sup]

Thanks. I am sure may more Inquiring minds want to know

[gotboostedvr6]

I've done this to mine with great success.

[mac90sup]

Yes thanks gotboostedvr6. I have seen your posts in ref to blocking off the very top holes. May consider your procedure and taking it even further by drilling and tapping all the side picks and systematically blocking the 5th,6th,7th and 8th hole to see what it does with the water pressure. Your thread on this procedure was Very informative and helpful. The Mercury side scoops in theory do a similar job by compressing the water entering the side water pick ups down to the last 4 holes. I am considering blocking off all of the side water pick ups to see what happens. Wanted to find out if anybody had done that and if they did, interested to find out what there results where.

[Chaz]

If the motor is low and you drag it thru the mud , park at the sandbar and use the skeg as a rear anchor or any activity like that which will plug up the holes in the front of the bullet , then leave a couple of the side ones open .
If you are moving the motor up and losing water pressure , plug up the "leaks" on the side and watch the pressure go up ..

[mac90sup]

Thanks for your response Chaz.