How to make hull water ramps

**Brad Zastrow** · 08-06-2024, 08:31 PM

I was told to add water ramps to the bottom of the sponson to help with water pressure. How is this done and what size should they be?

**David - WI** · 08-06-2024, 08:55 PM

Like this?

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**JPEROG** · 08-06-2024, 11:09 PM

David is correct. Adding a remote pick up as pictured is the correct way to go (mine will be closer to the keel to avoid propeller disturbance). Just carving ramps throws the majority of the water against the case "especially when its turned off of dead center". Teague makes some great adjustable pickups that are mounted to the transom at the keel. I have a set for my new project--they will feed into a strainer with a blowoff valve and into the motors from the strainer. I will also have a balance tube between the motors.

Brad, did you open up your stock pick ups yet? This and a balance tube need to be your first moves. All of my stuff has been opened up to a 5/16 slot and blended in with a die grinder and sand paper rolls. *the 36 has no ramps*

Joe

**Brad Zastrow** · 08-07-2024, 08:05 AM

I just do not understand why I have low water pressure on the outside motors. I drilled out the stock pickups like you suggested and I also have low water pickups going to a small distribution tank inside the boat and then feeding both motors to the large hose going into the thermostat. If I lower the motors I lose speed. At WOT the pressure drops to 10 lbs and water temp soars. If I steer slightly the pressure goes to 25 lbs. With my 300X motors I also used the low water pickup and they were only 1/4" below the bottom. Now I have the pickup as low as they can go at about 3/4"and still low on pressure. Center motor is great. The pickup are not real big like the I/O boats will use as shown in the picture.

**Brad Zastrow** · 08-07-2024, 02:46 PM

Here is what I am using now for pickups. Maybe I should look for bigger pickups?

**NICE PAIR** · 08-09-2024, 08:20 AM

Originally Posted by Brad Zastrow

I just do not understand why I have low water pressure on the outside motors. I drilled out the stock pickups like you suggested and I also have low water pickups going to a small distribution tank inside the boat and then feeding both motors to the large hose going into the thermostat. If I lower the motors I lose speed. At WOT the pressure drops to 10 lbs and water temp soars. If I steer slightly the pressure goes to 25 lbs. With my 300X motors I also used the low water pickup and they were only 1/4" below the bottom. Now I have the pickup as low as they can go at about 3/4"and still low on pressure. Center motor is great. The pickup are not real big like the I/O boats will use as shown in the picture.

If steering brings your pressure backup, you might look at your left/right alignment on your outboard motors. do you have check valves so the hull pick-ups cannot confuse the water issue? A good camera tells all! My $.02

**Brad Zastrow** · 08-09-2024, 09:21 AM

The engines are aligned. I check that frequently. With triples I have to be diligent about checking that. I do have check valves. Without check valves I think there would be zero water pressure at idle and slow speeds as the pump would push the water out the low water pickups. I REALLY APPRECIATE the help from everyone. After speaking with Joe Perog I have a plan. I need bigger jack plates to move the engines away from the transom. The setback is only 6" and the hull has no transom notch. Almost all cats were built with a notch and now the new cats are being built without. Also going to move the engines further outboard and get the props out of the tunnel on the outside motors. Right now, 4" of the props are into the tunnel. The boat runs great right now except in flat water I lose some pressure at WOT. Like everyone on this board I want faster. LOL.