Mini jacker install on short shaft engine

[Duramacr]

Today I installed my mini jacker on my 1542
Tracker. Engine is a short shaft 2015 Merc 20hp.
When I bought the boat the cavitation plate
was perfectly level with the keel of the boat
which is great. But I wanted to squeeze every
Mph out of the boat so I ordered a mini jacker.
The purpose was to set the engine back and lift
it 1 inch over the transom. Well it is easier said then
done. The problem I ran into is that if you don't use
the whole 3 inches of the jackplate and you want
to use less, the butterfly's to tighten the outboard hit
the transom and you can not tighten them. I had to buy
longer bolts and a 1.5 X 1.5 piece of wood to extend the
Jackplate even further so I couldn't tighten the butterflys.
Anyway I ended up going up an inch over the transom, but
since it's setback 6 inches the cavitation plate is only a 1/2 inch
over the keel . I'm gonna try it like this first and I have
probably 3/4 of an inch to go up or down . Here are some pics,
you can see how close the butterfly knobs are close to the transom.
Once I get this out on the water with this setup, I'll let you guys
know if there was a speed increase .

 

[Florida_Native]

I was considering that mount when I got my new motor but worried about putting extra strain on the transom. I have this Yamaha 25 and it's a tank, about 170 pounds.

I ended up having someone weld up a custom bracket.


Sent from my iPhone using Tapatalk

 

[Duramacr]

Wow that's nice but I wanted to move the motor
back as well. I have more pics but they take forever
to download . I don't know what's going on.

 

[Duramacr]

How high are you above the keel. That's a short shaft as well right?
Did you gain any speed?

 

[Florida_Native]

The cavitation plate about level or within an inch from the keel which is what the manual said to mount it. It's a short shaft, but without the mount I would have been below the keel and most likely to much in the water.


Sent from my iPhone using Tapatalk

 

[Duramacr]

More pics

 

[Charger25]

I put the same mini jacker on my 16' W/a 25 and lost 2 mph. running a new solars 10x13 prop. I can tell the prop is ventilating a bit however it doesn't "blow out " on turns. I'm sure I need to drop it down a hole. It does get on plane faster and stay on plane at a slower speed.

 

[lckstckn2smknbrls]

I have / had a mini-jacker on my 1436 jon boat running a 25hp motor. The boat is a 15" transom and the motor is a short shaft but it's a longer short shaft. I ended up mounting the motor about 2" above the keel and was still getting plenty of water to the intakes.