Installing mercury jet on a G3

BRWNBR

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Looks like a mercury jet shaft is 20", can I put that on my 20'G3 without adjusting my transom? Or will I need a plate to raise it?
 

BRWNBR

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Ok...what's the best/cheapest way to do that....? Hit up akmud to weld me a plate?
 

alaskanap

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Make sure the tip of the jet boot is in line with the bottom of the boat when trimmed down. Then drill the holes to mount the motor.
 

BRWNBR

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Lol well I probably won't know if it's worth a darn until I bend the back of my boat hitting the throttle!
 

Sobie2

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Crud! Them things are over 300 bucks!!

I used that setup and it was totally worth it. I was able to swap between the pump and prop lower unit. Just liberally apply anti-sieze on all the bolts (I was running in the salt though at times, maybe pure freshwater would be better. After a while I was wishing I had paid extra for the power version at $700.

Sobie2
 

Akgramps

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Adjustment is nice....... and necessary if you plan to swap between a jet & prop. If just running a jet I would look at some heavy aluminum angle, 3" X 3" X 1/2". Once you get it set right you shouldn't need to change it. If you have a tunnel you can extend the roof of the tunnel over the foot with a rubber flap. This will allow some grace as to running the foot slightly higher.

If no tunnel then a piece of UHMW will help

Lifts are handy whether manual or power, and they do allow some fine tuning, however they are heavy and the set back can be a big negative. Particularly so if the bottom is less the 6' wide. IMO

And spendy.....
 

Sobie2

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If just running a jet I would look at some heavy aluminum angle, 3" X 3" X 1/2".

Like these:
CMC-50012-5-INCH-verticle-extension-for-jack-plates-transoms-installed-500.jpg

A link to an online retailer off of their site is selling these for $143.16 But I think Dewey's Cook Inlet stocks the whole CMC line.

Sobie2
 

.338WM

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I measured then cut a piece of wood the proper height and thickness, then had someone weld for me a riser using 1/8" aluminum shaped like a "U", but squared off-or deep "channel". Inserted the wood to fill the airspace so as not to crush the aluminum when I bolted the outboard on. So I had two bolts through the outboard and height adapter mounting plate/transom described above, and two bolts through the outboard and transom below. It worked happily for many years in that fashion and never had an issue with it. The adapter was long enough overall that I also secured it with two more bolts near it's lower extreme.

Put another way; set the riser down over the top of the transom(if memory serves it extended 6" or so below the top of the transom), about an inch from the bottom of the riser I drilled two holes to insert 1/2" bolts with nuts and washers securing it to the transom, then set the outboard on, marked the mounting hole locations on the outboard bracket, pulled the outboard off, drilled the holes then installed the outboard and bolted it down.

Just be sure you have the correct height for the jet foot before you drill. :) BTW this was for a 55hp 2 stroke, factory spec. said it weighed 206lbs and it was on a 16ft Jon boat.
 

dkwarthog

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Get two peices of 1/4" aluminum sheet cut to about 3 or 4 feet long by two feet deep. Have a lip bent on each piece that is the thickness of the transom. Put them on the transom so that one lip lays over the other. Adjust to the right height and then bolt them to the transom (sandwich the transom between them with thru bolts). Probably 50 bucks or so, if I remember right.

After reading the post above mine, the idea is similar, but use two separate pieces instead of having a U in one piece.
 

Cresent Hills

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It doesn't sound like you have bought aluminum and had it broke lately.. Aluminum is almost the cost of bottled water these days... $50 is awfully conservative unless you fine someone with those pieces in the scrap pile and has a brake that can work 1/4" material.

I am continually amazed at folks that want to cheap out on a transom riser to hold a multi thousand dollar motor on the back of a boat that was not engineered to hold a 250# motor up 7 inches above the transom, let alone bash across rocks and sand bars... it happens.. trust me and to have the cheapest weakest link holding your whole investment together boggles me.. if you think a $300 motor jack is spendy, wait till you buy impellers and sleeves and jet foots and re weld the transom after a few good hits... if you bought a jet boat to save money you made the wrong choice.. even the best drivers have bad days... it's part of the game and we just get out the wallet and move on.. live and learn..

Tom

Get two peices of 1/4" aluminum sheet cut to about 3 or 4 feet long by two feet deep. Have a lip bent on each piece that is the thickness of the transom. Put them on the transom so that one lip lays over the other. Adjust to the right height and then bolt them to the transom (sandwich the transom between them with thru bolts). Probably 50 bucks or so, if I remember right.

After reading the post above mine, the idea is similar, but use two separate pieces instead of having a U in one piece.
 

BRWNBR

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I've got a 50hp prop on it now and would like to go to a 90/65 jet to give me more versatility. Right now pretty limited
To flowing water I can run. Never had a issuing trimming it out. Trimmed up nice it scoots right along about 29mph.
In no way did I plan on spending money to save money...just suprised at the cost of a extension. Totally understand what you mean about not using a cheap connection...1500 dollar rifle 900
Dollar scope and rings off your granddads old .22....

Where does the jet foot need to be?
 
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