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innos
24-06-2013, 08:01 PM
My transom on my 17r is 20inch and i am looking to repower. I am looking at getting another outboard with a 20inch shaft but just curious what are the pro's and cons if i got my hand on a 25inch shaft outboard and wacked it on the back of my haines 17r using a jacking plate???? Just worried about strain on the transom and being a bit top heavy.

stevemid
24-06-2013, 08:58 PM
I've just commissioned the making of jack plates out to 12mm aluminium plate welded into a "C" section form. I've made them long enough (420mm) so that I can have 4 bolts through the original mounting boards. IMO you're only top heavy (and thus torquing the transom) when trailering. When you're motoring, all the force is perpendicular to the transom, in line with the length of the boat.

The value of a longer leg is getting the power head and the air intake clear of mist which shortens 4St engine life. My marine dealer said they can't certify a new engine for warranty if there is a mist problem.

innos
24-06-2013, 09:25 PM
what about at rest??? I would have to jack mine up around 5 inches if i got a XL shaft outboard as my transom is only 20 inches.How heavy is the jacking plate??

Troy Wood
24-06-2013, 10:07 PM
These plates are about the best one to use to raise your 20 inch transom to run a 25 inch motor.
They only have 4 inches of set back and are a integrated unit not a multi piece setup.
They are not to bad for weight and we have used them up to 300hp. They are a direct fit
And give more than enough vertical lift.
Here is a link below.

http://www.ebay.com.au/itm/Detwiler-Outboard-Jacking-Plate-Manual-4-/221192742533?pt=AU_Boat_Parts_Accessories&hash=item33801d6685&_uhb=1

fandtm666
25-06-2013, 07:46 AM
i have this one from vance in the usa , very solid build and great product.

http://www.ebay.com.au/itm/Jack-Plate-JPL4400-Adjustable-4-Outboard-Jackplate-/290787292381?pt=Boat_Parts_Accessories_Gear&hash=item43b445f4dd

bay cruiser
25-06-2013, 08:16 AM
I considered this option recently also...

Keith Faulkenhagen from Jeffer's Motorsport Marine at Burpengary, Qld has some basic CMC transom extension plates for around $300. They weigh about 5kg and require six bolts through the 20" transom (4 original and 2 new ones). Other types of a plate systems weigh around 15kg.

http://www.cmcmarineproducts.com/products/Outboard-Jack-Plates/Static-Height-Plates/CMC-Static-Jack-Plate-5-inch-vertical-extension

innos
25-06-2013, 10:00 AM
Why did you not go with the jacking plate bay cruiser. I am just worried about it putting.to much stress on the transom as a it will be sitting pretty high. And I do not want it to change the way my boat rides

bay cruiser
25-06-2013, 10:50 AM
I ended up with a 20" motor. But, just this morning I found out that I need to have it replaced (for reasons I will not get into here), so if I find a new motor that's a 25" leg I may end up using the plates anyway.