Allison jackplate for shorty - how?
- Thread starter aeneas
- Start date
K.Kiser
Well-Known Member
Not all plates will accomodate this, If I remember right... It's been a while since I was knee deep in that stuff, but I think if it's a jackplate for a 20" shaft you'll end up around 1"-2" too high when using a 15" mid...
The one I have you take it apart and flip one half.
hack02
Well-Known Member
K Kiser is right. Some of them won't work no matter the combo. Just have to try all the different configurations.
h2oskiier30
Well-Known Member
Yours is not the style that can be flipped, without making some modifications yourself. You'll have to drill new transom bolt holes in the plate to make it work.
In your example above, you're flipping the wrong half of the plate. You flip the half that fits to the transom...not the "back" half. As said above, you'll have to switch sides with the two flipped pieces, too. You end up a lot more than 1.5" lower, as well. Works great for a 15" motor.
I'll take a pic of mine when I get home this evening and post it if I can remember.
In your example above, you're flipping the wrong half of the plate. You flip the half that fits to the transom...not the "back" half. As said above, you'll have to switch sides with the two flipped pieces, too. You end up a lot more than 1.5" lower, as well. Works great for a 15" motor.
I'll take a pic of mine when I get home this evening and post it if I can remember.
Last edited:
Brack
Well-Known Member
Ditto.......
white03
Active Member
I believe when they said "flip it" they were talking about the hydralic plate, not the manual
Ok. Is it worth the effort or should I buy a new one? Is the one on the boat a Bob's (I know it says Allison on it but I think I have heard that they are manufactured by Bob's)? If a new is the best alternative, which one should I go for? I need a manual as weight is an issue with my engine (Merc 200xs - 434lbs). How much setback? Any tips on good prices?
Perhaps somebody has an Allison Jack Plate for 15" engines 8-9" setback for sale?
Perhaps somebody has an Allison Jack Plate for 15" engines 8-9" setback for sale?
Last edited:
h2oskiier30
Well-Known Member
Nope...manual. The hydraulic plates might can be flipped too, but I've never heard of anyone doing it. Seen it done with the manual plates many times (including mine), and all of the newer Allison manual plates are "convertible"...meaning they can be flipped to be used with either 15" or 20" motors.
K.Kiser
Well-Known Member
The Allison plate isn't a Bob's, and I've come to the conclusion that the Allison plates are better than the rest, as they are geometrically square and very rigid where most of the others aren't... I would go no less than 9"(ish), and wouldn't feel wrong about using a 12"...
h2oskiier30
Well-Known Member
Aeneas....after taking a look at my jackplate, and reviewing your plan, you're on the right track. I misunderstood a little of the wording without being able to see mine. By "outside", I thought you meant the rear half of the plate.
I believe your plan is worth the effort...especially given that you are overseas and the shipping alone on a new plate would be ridiculous high. The only extra "effort" would be drilling the new transom bolt holes and swapping the "A" bracket to the "B" position you mentioned in your illustration. Either way, new or modifying your current one, you're having to remove the jack plate.
Here's a pic of mine. It is coming off in the next week or two, to be replaced with a newer Allison true convertible plate...and will be for sale (although I may already have a buyer). It's a 9"...
I believe your plan is worth the effort...especially given that you are overseas and the shipping alone on a new plate would be ridiculous high. The only extra "effort" would be drilling the new transom bolt holes and swapping the "A" bracket to the "B" position you mentioned in your illustration. Either way, new or modifying your current one, you're having to remove the jack plate.
Here's a pic of mine. It is coming off in the next week or two, to be replaced with a newer Allison true convertible plate...and will be for sale (although I may already have a buyer). It's a 9"...
h2oskiier30
Well-Known Member
The only other manufacturer that I've seen use the same adjustment as the Allison plates is T&H Marine, with their two piece "Hi-Jacker" series. If I had to take a guess, I'd say it's a good bet that T&H builds them for Allsion.
Like K. Kiser, I prefer the Allison plates because (1) they're solid all the way around, and (2) they have fine adjustment capability. The Rapid Jacks are very popular and a very good, well-built plate, but you only have the capability of 1/4" adjustments with it.
Like K. Kiser, I prefer the Allison plates because (1) they're solid all the way around, and (2) they have fine adjustment capability. The Rapid Jacks are very popular and a very good, well-built plate, but you only have the capability of 1/4" adjustments with it.
Thank you! That looks exactly like what I had in mind. I was not so good at describing how I meant so kudos for picking it up!
I will see if it is possible to do the necessary adjustments on my jp as there are drilled holes for the prototype Skid Planer... I have just in case in an e-mail asked Bill @ Allison for a price of a jp for 15".
How much setback would you recommend taking into account that it is a less powerful and slightly heavier engine than you guys run? SS-2000XL/Merc 200xs shorty.
Last edited:
h2oskiier30
Well-Known Member
Allison jackplates in the size you're looking for are $575 plus shipping from Allison...I called a couple of weeks ago inquiring about one before finding a used one.
I will let another SS2000 owner give you advice on setback, as I have never owned or even driven one.
I will let another SS2000 owner give you advice on setback, as I have never owned or even driven one.
hack02
Well-Known Member
I've re drilled a few. Just measure and then re-measure about five times before you drill. You can get a machinest to cut the new groove in the plate where it meets the top of the hull. Look closely and you'll see what I mean. Not a bad job.
Great! If I convert the jack plate I will have the modifications done at a workshop, both the drilling and the shaving and grooving (I noticed that there is an aluminium rail at the joint on the transom).