25 Eliminator Daytona twin 300r water pressure issue

[city]

Water pressure drops above 50mph and temperature rises specifically on the port engine. Looking for suggestions.

Here is the setup:
Sportmaster HD 1.60 lowers
12-1/4" setback on bracket including -3.6 degree wedge
2-3/8" up from running surface of hull to center of nose cone of drive
Running Hill Signature 400 15.25 x 30P props (turning out)
No jack plates

Pressure on Port motor 5 psi
Pressure on Starboard motor 10 psi

pressure drops as trim is applied

Dealer replaced water pump impellor and checked screens for debris

Thank you for any suggestions

[djlinkdog]

Stupid question, but at high speeds and lift are the outboards low enough? Just seams odd with the sport masters to do this. And I’m assuming it’s a tunnel V? Without a jack plate to lower it will be hard to find a easy answer

[Pulsare2400]

If we understand you correctly the prop shaft is 2 3/8" above the bottom of the hull. Is that correct? I have never worked on a Daytona Eliminator so I do not know how high they typically run dual engines on this hull but more than 2" above the bottom seems a bit high? Too bad it is not hydraulic jack plates like the other member said, because it would be easy to lower them 1/2" at a time and watch what happens to the water pressure. I would try and find out where other people with the same hull run theirs to get an idea if they are similar to yours or lower.

[JPEROG]

Go pros don't lie. Mount a couple on transom and play it back to see where the water is hitting the case. Water pressure will always drop on a sportmaster case when trim is applied (the nose drops which causes drag and the water goes under the pick up), they are designed to run neutral or negative at speed.

Joe

[city]

boat starts to porpus at 60 without up trim and wont stop A little up trim and it takes off but pressure drops thanks for the info

[djlinkdog]

boat starts to porpus at 60 without up trim and wont stop A little up trim and it takes off but pressure drops thanks for the info

I think your outboards are not low enough, and the difference between water pressure between the motors can just be your weight on that side of the boat lowering it a bit unless you got center steering?

[Merc 2.5]

I think couple 3 or 4in plates would be good investment, if u dont need bow lift stay with 3 or 4in setbacks , if u can use more lift get some wider 6-10in. Sounds to me it wants to go when u trim up but pressure stops you? I'd lower em 1 bolt hole , but jackplate u mite even gain little extra on top

[mbrown2]

That seems high. I remember my F26 with 300x's center of nose cone was around 1" up from the bottom of the running surface.

[city]

That seems high. I remember my F26 with 300x's center of nose cone was around 1" up from the bottom of the running surface.

i wonder if turning the props in would change anything

[SUNKIST]

At 75 80 mph take a walk back and see where the water is hitting your lower unit. Should be right at the intake top of the bullet. Smooth water and a competent driver. A Video also.

[Chaz]

Gotz water ramps … ?

[Davidlake]

Water Ramps like this?? Sure do!

[Hydrogasm]

Another thing to do would be to install transom mounted water pick ups. This was how my Cougar 22MTR was rigged at the factory, so I always have good water pressure now matter how high I jack the engines. The boat also has Bob's 6" hydraulic jack plates as well. I hope you get it figured out.
Thanks
Gary

[FUJIMO]

...proper tie bar adjustment. toe in or toe out, is critical, depending on which direction your turning the props. one tie bar adjustment does not work for both rotations. on a twin install that is surfacing, be they inboard or outboard, it has always been common belief by even the best performance(and non performance) riggers out there, that the leading edge of the gearcases be adjusted pigeon-toed when the propellers are rotating outboard. I believe it to be, in fact, the exact opposite, and have proven this to the likes of bobby moore, don schwebs, bob latham, and others... drive alignment at speed affects water pressure, prop performance, handling, lift, and on & on... its important.

[FUJIMO]

...its also kinda weird to think, that just the propellers alone, can affect water pressure. but they can. they're particular design, blade count, rake, blade cross-section design, hub type & length, etc., all can alter a side water intake gearcase & sometimes bottom or front water intakes flow function...food for thought.