Hi!

We mounted two Merc 2.5 EFI SS engines on our ol Phantom 25 last summer. The engines have Brucato PSU and CLE lower units. Propshafts are approx. 1,2 inches below the bottom. The engines are mounted directly on to the transom 19 inches senterline senterline. The SS bracket has two inch built in setback. Weight is approx. 3.000 + pounds.

We used a single Promax 300 SVS from 1998 to 2006. Top speed was 76 mph at 6.300 rpms spinning a A45 Tempest 25 prop. CMC powerlift and 7,5 inch setback. Propshaft approx. 2,5 inches below the bottom.

We have tried some props, although its not easy to get hold of them in Norway for testing. Lucky us we got the chance to borrow some props this summer.

We feel we have more speed to gain. Here are the results so far:

-Bravo One 14,5 x 28 pitch stock = 84 mph at 6.400 rpms (far too low rpms) - spinning out - a great deal of positive trim needed. 2 persons.
-Mirage Plus 14,5 c 27 pitch stock - 86 mph at 6.800 rpms (still too low rpms) - spinning out. Required lot of positive trim. 2 persons.
-Hydromotive Quad X O/B 15 x 25 lab finish - 84 mph at 7.100 rpms - spinning in and out. Lot of lift from the props, both tail and bow. Required less positive trim than the Mirage. 2 persons.
-Hydromotive Quad X O/B 15 x 25 lab finish - 86 mph at 7.400 rpms - spinning in and out. Lot of lift from the props, both tail and bow. Required less positive trim than the Mirage. 1 person.
-Chopper 14,5 x 26 pitch lab finish - 84 mph at 7.000 rpms - spinning out. The props are second hand, have been labbed by Mazco. Require lot of positive trim. Strange... 2 persons.
-Hoss Hyperdrive 14,5 x 26 - 82 mph at 7.600 rpms - spinning out. Required lot of positive trim. 2 persons.

We need to spin the props outward due to stability. We are certain that spinning in will be ok at wot using the tabs to stabilize it, but at high seas spinning in proved to be unsettling. The boat is only 5,5 feet wide. When spinning out, the boat runs on rails in all conditions.

There are two scenarios:

a) Rise the engines one hole, thats it 0,6 inch. Then maybe the speed increases due to less drag. But the need for positive trim works against this. Testing will tell.

b) Add a little more setback, typically 2 inches spacers to a total of 4 inches. Previous owners of Phantom 25 running twins using powerlifts have run into problems, espesially in high seas. So

What do you think?

We also know that the PCU is set very conservative. We think they are set 5-10% rich, so its more power there. In the spring we will get hold of EGT's and fineadjust the PCU's. The engines have just been rebuilt, so we think thats the reason why the PCU's are set rich.

The best three props have been:

- Mirage Plus 14,5 x 27 stock 7/10 condition (86 mph - 2 persons)
- Bravo 1 14,5 x 18 stock new condtion (84 mph - 2 persons)
- Hydromotive QIV X O/B 15 x 25 labbed (84 mph - 2 perons / 86 mph 1 person)

Labbing the Mirage Plus or Bravo One should improve the top speed further?

Other suggestions?

Cheeers and thanks!

Toffen G and Kim Heidi - Norway