What Happens?

[Abe's Rocket]

If you put a 25 inch shaft outboard on a boat that is set up for a 20 inch motor? cavitation? drag? thanks for your replies. Abe's Rocket.

[ScottM]

No cavitation, but lots of drag. Your performance will suffer as well with the lower unit that far in the water.

Just something to think about - get a manual jack plate ($300-400) with 5" of vertical travel and you should be all set. You really want the engine's trim tab to be within 1" of the boat's keel for optimal performance and fuel economy.

[Abe's Rocket]

thanks for the reply. who makes the jackplates? outboard mfgs?

[ScottM]

Abe,
My father bought a Rite-Hite last season for his 23 Sceptre. They are made by RM Industries, but there are other mfgs out there.

Here's the link for Rite-Hite...

http://www.rmind.com/jackplates.php?...9199.232.152.9

[Abe's Rocket]

thanks, i've bookmarked that bad boy and will keep that as an option when i get a new motor. cheers

[ScottM]

Abe,
Here's a couple pix of the Rite Hite on my father's Sceptre...

[Abe's Rocket]

nice rig! thanks

[Rufridr069]

Thats the same bracket on mine now....and I thought I was crazy. Why the heck put a jack plate on a 23' boat? Every one of my boats had either Stainless Marine or Armstrong brackets. But I am changing that jack plate to a Stainless Marine 18" bracket which I picked up at the Marine Flea market for 300.00 brand spankin new.

[ScottM]

Thanks Abe.

Why the heck put a jack plate on a 23' boat?

Simple - preference. Due to the additional 5" notch in the transom, my father needed to move the engine up and back so that the engine would tilt all the way out of the water and not hit the splashwell. Since the boat has a sound transom, going the full bracket route didn't make sense.

Although the engine was put on the boat at the same time as the jack plate, it's hard to know for sure what, if any, performance gains it has produced. But I will say that the boat now planes at 15mph when it used to take 18-20 with the old 'Rude 225 bolted directly to the transom spinning the same size prop (15x15 SS). So from that standpoint, the addition of the jack plate has served its purpose very well. With these boats, if you hang an engine on a Stainless or Armstrong non-flotation bracket, that engine is getting dunked with 2 guys in the back. Not the case with the jack plate.

[Rufridr069]

Sounds logical. While we are on the subject....I worked the Dusky fishing tourament on sunday and ran into the Mercury Reps. They told me they have a repower special coming around in nov-jan where they will give you a 5 year warrantee along with special financing.