Grandsport setup

[simpson_3]

I’m looking to buy a Grandsport and wondered if it’s okay to run a 225 hp 15” mid section.

 

[dubmoney]

It is OK to do that. Only draw back is you need to be more careful coming off plane. I helps to install skip planer, and maybe foil. I how ever don't have either, and have after market cowl which does let a little water in. I believe the factory alien cowl may do a better job keep water out. Some, people may say the 20" mid flys the nose better. It is just a matter of lip adjustment. All my opinions.

 

[dubmoney]

I might also mention that you may need a differnt jack plate if you buy one with 20" stuff. Although, I did end up using my 15" on a Detwiler jack made for a 20" motor, it works OK.

 

[DOUBLE J]

I had both on Grandsports (20 & 15) and I prefer the 15”. The handling is so much better with the 15”. I’ve ran 5 in boat and don’t do anything special slowing down. I’ve also prefer the foil but not the skid planer.

 

[RiverRat71]

I think it probably depends on the weight of the engine. I have a GS with 225 20". I would say handling would be better with 15" but my engine weighs right at 450 so if it had a 15" mid it would likely get swamped easy. Mine is a 2.5 XS so I guess if youre talking about a Promax it might be a diff story. Robert Cross here on the forum has a new GS with a 225 XS and a 15" mid, & I think his old GS had a 225 Promax with a 20". He might be of some help. RR

 

[SLOmofo]

I know nothing. Butt I do have a 1994 XB2003 with a 3.3 OMC Taylor 16" mid sports master lower...nice and heavy. When I first was setting it up if I was standing at the transom the waters would be at the rub rail. On decel water would wash over the back deck, if I wasn't careful. Once I filled the setback with foam chunks, standing at the back water would be 5" to 6" below the rub rail and no water on the deck.

 

[RiverRat71]

I know nothing. Butt I do have a 1994 XB2003 with a 3.3 OMC Taylor 16" mid sports master lower...nice and heavy. When I first was setting it up if I was standing at the transom the waters would be at the rub rail. On decel water would wash over the back deck, if I wasn't careful. Once I filled the setback with foam chunks, standing at the back water would be 5" to 6" below the rub rail and no water on the deck.

Hey SLO, I like that! I have an Allison hydraulic jack on mine so there is no room for big balls or a lot of foam but do you think a couple of 7" balls on top of the planer under the jack would do any good? Been debating on trying that. Sorry op, not trying to jack this thread. RR

 

[SLOmofo]

I think something is better than nothing. Inside my setback is the trim ram, I just cut pieces to fill around it. I'd guess there is a way to partly fill a hyd jack plate. I also think the water inside the setback adds to the overall weight of the boat during take off, that is until it drains out.

 

[DOUBLE J]

My favorite on the GS is a 15" 280. I've been running it with a 6'' set back bracket, 5.5 " hyd. jackplate and a 1" wedge (total of 12.5" set back plus the 2" setback which is in the factory 15" mid ( grand total 14.5" set back ). At one time I did the volleyballs in the bracket and just didn't like the look. I usually run with just a passenger and I don't even worry about coming off plane. I have since purchased a STR adjustable manual jack plate (12-14") which I'll be installing soon.

 

[ROBERT CROSS]

I knoe nuyhing too...

Bob

 

[SLOmofo]

LOL

 

[2Fast2Pass]

15" works well for this one!!