I have a 2001 29 ft, single engine Fountain, with a 575SCi

Just repalced my broken XR drive (2001) with a new 2005 XR drive - old drive had a low water pickup only -- new drive has a combination pickup.

Mercury says combination pickup is a faster drive, therefore we all assumed it was more streamlined with better water flow to prop.

Boat ran 86 to 87 mph before with a 32" lab'd B1 at 5400 rpm.

Before, when coming on plane at 3200 rpm, prop would blow out just after boat nosed over, but when i reduce rpm back to around 3200, prop would re-bite , boat would keep accelerating, and off I go.

With the new drive, prop would not re-hook - it just kept slipping no matter what rpm i backed off to - and boat eventually fell back in water

So - installed a 1-1/2" space and problem solved but lost way to much speed and rpm, even with a smaller 30" prop -

so we installed a 1/2" spacer and with two adults in the boat, it was back to OK with speeds back to 87 mph at 5300+ rpm -- boat acted like it used to getting on plane.

This past Saturday, had two adults and 3 small kids in the back and Blow out again -- Had to have kids move up front to get it on plane --

Why the problem with a supposedly more hydrodynamically efficient drive ???? Is it the upper water pickup holes ?? Any suggestions what to try next ?? I am thinking trying a 1 " spacer and then a low water pickup only and see what happens

Interesting, Keep us posted!

are you sure your original drive was the same ratio as the new drive?? Almost sounds like you had a 1:65, and now you have a 1:50.

DISREGARD.......MISSED THIS LINE......

it was back to OK with speeds back to 87 mph at 5300+ rpm