The jack plate mounting assembly has a t. Most competitive brands can only be adjusted from the top. Th Marine Pro Hi-jacker 10 Jack Plate - Jackplate - Used - Nice $250. Rather than the stern “squatting down” in the water initially, the way it would with a standard engine mount and the engine trimmed up, the stern moves forward as the jack plate allows the engine’s thrust to work, keeping the prop high enough to miss the bottom. Please study the diagram to familiarize yourself with engine and boat terms. The Mini-Jacker jack plate is designed for clamp-on mount outboard motors up to 35 HP. The one-wrench design allows you to easily adjust the jack up or down from the transom of the boat without removal from the water. Th Marine Atlas Hd Hydraulic Jack Plate 8 Set Back Mercury 350 400r Ahj-8vhd-dp $1,699. It's an all-purpose beast that will change everything you thought you knew about boating in extreme conditions. 99 Outboard Transom Wedges - Reversible - Add 5 Degrees of Tuck. Enter your search keyword. How to adjust outboard engine. Re: Jack Plate position ?? « Reply #17 on: April 15, 2011, 08:11:41 PM » Jerry has the correct answer. The jack plate mounting assembly has a t. It's the 8" to 15" plates you need to know about because of the tremendous load they place on you transom. We have the parts you need to repair your jack plate or tilt trim unit. An actuator is provided to raise and lower the lift plate relative to the transom plate. Nice-10GC Engine Generator.



The exclusive patented Rapid Jack’s Ratchet lets you move your outboard engine from lower positions for family boating to upper positions for maximum speed in minutes. The Speeditwin required the jack plate be all the way up. Roll of Irrigation Hose with Ends. The difference between a 16-7" Whaler's speed with its motor set way too low on the transom with a mediocre propellerand set at the optimal height. Essentially, jack plates lift your motor higher out of the water. Wise 55 Bench And Lean Back Set Th Marine - $1,737. When it comes to lower units, Bob’s Machine has a line of nose cones and stabilizer plates that can help you dial in your rig. Only experiment, and perhaps experience, will tell you that. Raising the motor actually lifts the boat out of the water, enabling it to move faster. To raise and lower my jack plates, I use the jack from pickup truck. I have a 19' STV with a Merc 2. The jack plate further includes a motor lift including a lift plate extending between a first bearing and a second bearing, the channels adapted to conformingly receive the first and second bearings. Manufactured from aluminium extrusion and marine grade 316 stainless steel fasteners. Would a jack plate work to lower a motor with a 21" shaft low enough? Problem will be that your power head will be awfully close to the water line. We have boat engine parts, inboard engines, outboard engines, lower units, and stern drives from the brands you know, love, and trust: Mercury, Suzuki, Mazda, Volvo Penta, Tracker, Yamaha, Evinrude, and others. Brand New StumpysFabWorks boat lower unit jack.



Evinrude Johnson Outboard Lower Unit 115 Hp 1979 Long Shaft P 389819 Works. eBay is recognized as the top online shopping site with the lowest price ranges, swiftest shipping and delivery and best customer care. Part Name: Lighting Bolt Quick Adjustment Universal Outboard 6 " Manual Jack Plates Part Details: Great used Condition Outboard jack plates. Zoom zoom! Power up with new discount boat engines from Great Lakes Skipper. The Rapid Jack is available in setbacks ranging from 4" to 15" and is available in the heavier duty Magnum series. Does anyone have experience with the jet outboards? I currently have a 1654 tracker grizzle that I run up and down most of the rivers with but cant determin if I should use a small jack plate or upgrade to a 40 hrs jet outboard to allow me more access to the upper mississippe and st. A jack plate is a hydraulic device that lifts and lowers a boat's main outboard motor. For a 2 post, you'll need to go down at least 2 feet. The outboard engine hydraulic jacking plate actuator is self contained with its own hydraulic fluid reservoir. 00 Remanufactured Yamaha 115 Hp 4-cyl 4-stroke Outboard Cylinder Head, 2000 And Up Seastar Outboard - $1,448. Manual Tilt on Johnson Outboard stuck down Page: - I have a 2004 40 hp Johnson Outboard with manual tilt and My engine's manual. A hydraulic outboard jack plate is mounted to the transom of the boat, then the outboard engine is mounted to the moving part of the plate. see notice lower port side bolt access see notice 12" x 1-116" od washers (supplied) engine mounting bolts transom side of jackplate 1. Aluminum Propellers; Prop Wrenches; Stainless Steel Propellers; MASTERTORQUE HUB KIT; Prop Wrenches, Pullers & Accessories. Outboard Jack Plate In the event that you are considering Outboard Jack Plate, you have definitely come to the appropriate place. Re: Single outboard for a catamaran? The centrally mounted 60hp outboard on my 40' sailing catamaran would lose it's grip on the water quite often before I added a stabilizer or whale tail. The joys of my first boat start,I have a 18'5 key west bay/reef with 4 stroke yamaha,powerpole,trolling motor and my Jack plate is stuck all the way up. The jack plate mounting assembly has a transom plate and a pair of spacing brackets with jack plate rails. Outboard Motor Accessories lower engine RPM.



Extreme Performance Hydraulic pump and electric drive technologies deliver superior anchoring. With the Porta Hydraulic Transom Bracket you get both - the setback, with its advantages, and the vertical movement range - of 12" to 24" - much more than is offered by any. Atlas™ Hydraulic Jack Plate by T-H Marine®. Has anyone used any of the mounts to get their back from the transom? Also, advice wanted on outboard set back to increase efficiency. A jack plate for vertically raising and lowering an outboard motor mounted on a boat. through the transom, a jack plate would allow correcting the height of the engine installation to the true shaft lengths. eBay is recognized as the top online shopping site with the lowest price ranges, swiftest shipping and delivery and best customer care. It will fit the following applications with a 1-1/4" diameter shaft: OMC Cobra sterndrives 1991 thru 1993, Johnson/Evinrude. Thinking of purchasing a 37hp mud motor to switch out for duck hunting. Today, however, a number of outboard builders offer models with high-performance lower units on production models. After a few months of being able to raise the jackplate under power but having to stop or idle to lower it. Just my 2 cents. The kickup portion of the assembly is chained to prevent over rotation of the outboard when a submerged object is struck. Fast Tail attaches under the cavitation plate rather than on top. The outboard engine hydraulic jacking plate actuator is self contained with its own hydraulic fluid reservoir. Outboard and Inboard Boat Engines. Hydraulic Jack Plate by CMC®. Re: Setting up an outboardprop, jack plate, and anti vent plate questions You can try putting a fin like an se sport 300 on it & itll help alot, if all out speed is not your main concern. Bobs is great as well as a few other companies out there. that is what the plugs are for.



Advantages Of Using Hydraulic Jack Plates And How To Use It On Your Boat. By Miss Cabbit in Boats. Some bay boats and flats skiffs also have jack plates to facilitate adjustments in outboard height. Install A Jack Plate On An Outboard Motor A jack plate gives you and government over your boat by allowing you to not single trim the Engine up and down, on the other hand to elevate and lower it, so you can impel the Engine in impartial trim, while using the jack plate to lift the Engine higher, Towards the hull, for shallow inundate operations. A jack plate enables your outboard to provide optimum performance in shallow water. Worst case --- four new bolts thru the transom to mount the jack plate lower. Outboard Jack Plate In the event that you are considering Outboard Jack Plate, you have definitely come to the appropriate place. Tools - Shop Supplies Outboard Tools. I am upgrading to a 40 h. Manual power lift and jack plate units for boat outboard engines. Designed to raise and lower your outboard motor, hydraulic jack plates will help to improve your boat's performance by improving the gas mileage while increasing speed. Atlas hydraulic jack plate is designed to meet the demands of today's high performance outboards. We have boat engine parts, inboard engines, outboard engines, lower units, and stern drives from the brands you know, love, and trust: Mercury, Suzuki, Mazda, Volvo Penta, Tracker, Yamaha, Evinrude, and others. This jack plate has a slot adjustment of 6" to move your outboard up and down so. Lower 880686t56 Sma5629 Mercury 30 Unit 13x24, Shaft 300hp 1. 500 inches at a maximum height to raise your long shaft engine and make it workable on a.



This spreads the load evenly throughout the plate rather than on the individual bolts. The Jack plate allows a Boat to run in shallower water than a standard engine mount. Because this is home made, there is no guarantee that another home-made jack plate, even if the same design, will act the. The lead screw assembly sets the plate height and the Side Locks are used to hold the position. The Porta Bracket also allows the gearcase to be raised above the bottom of the boat without tilting, allows the propulsion line to remain parallel with the direction of the boat, and eliminates the need for lower unit anti-fouling paint. BRAND NEW- MJ-1 Mini-Jacker by TH Marine •Cast aluminum •Designed for clamp-on mount outboard motors up to 35 HP. com can add a Honda outboard to any of our inflatable boat packages. A jack plate for vertically raising and lowering an outboard motor mounted on a boat. The Rapid Jack is available in setbacks ranging from 4" to 15" and is available in the heavier duty Magnum series. Geoscientists still struggle to understand the strong and repeated intracontinental deformations so beautifully wrought in Colorado and surrounding states (right). Family Owned & Operated since 1984, determined to serve You. Transom Trauma Boat transoms can be subjected to. The sliding part of the jack plate is about 1" above the stationary part of the jack plate. 6hp 2 Stroke Heavy Duty Outboard Motor Boat Engine W/water Cooling System. Does anyone have experience with the jet outboards? I currently have a 1654 tracker grizzle that I run up and down most of the rivers with but cant determin if I should use a small jack plate or upgrade to a 40 hrs jet outboard to allow me more access to the upper mississippe and st. Jack plates allow you to raise and lower your outboard motor so as to operate at peak performance even in shallow depths. This thing is class A #1 junk. A correct conventional installation would generally place the ant ventilation plate on many engines about even with the boat bottom when the engine propeller shaft is parallel to the boat bottom (Figures 7-8 and 7-11).



Stainless steel bolts. bolts holding the vertical support members of the splash plate assembly to the transom mount. This tool operates hydraulic pressure at the control of the operator to maneuver place. We have the best deals on Outboard Jack Plate so stop by and check us out first! Boat Parts and Accessories For Sale. 95 Seastar Outboard Jack Plate 12 Set Back Up To 300hp Mercury Yamaha Suzk Jp5120r. The Freedom Outboard is a true marine engine. You can use the marks for future reference in moving the plate. Our site has located a broad assortment at an array of prices. Setback Plates for Outboard Motors. Designed to raise and lower your outboard motor, hydraulic jack plates will help to improve your boat's performance by improving the gas mileage while increasing speed. Can I hang the mud motor on the jackplate? I know I will have to lower it as I have it at it's highest setting for my outboard. A hydraulic outboard jack plate is mounted to the transom of the boat, then the outboard engine is mounted to the moving part of the plate. Shop, read reviews, or ask questions about T-H MARINE Atlas Hydraulic Jack Plate at the official West Marine online store. Elite Distributor. Subscribe to our free e-newsletter, and get new tips every two weeks. The rod-and-slot lift system can handle motors up to 300HP with a Heavy Duty option up to 400HP. Great Lakes Skipper has outstanding discount prices on top-quality new and replacement marine parts and boat engine accessories, including outboard motor brackets, boat jack plates, boat motor mounts, marine engine mounting brackets, and more boat engine jack plates and motor mounts from brands like Trelleborg, Gil Marine, Panther, Pooderbuilt.



then lower in 1 inch increment and tighten all bolts back up. Obviously it helps to know approximately how high you need to go. Jack plates are used to improve an outboard boats speed, holeshot, fuel efficiency, and the boater navigate in shallow waters. Shop with us today. Outboard Engines & Components Find Outboard Engines & Components Parts For Sale in Boat Parts. com has ranked N/A in N/A and 180,005 on the world. The jack plate mounting assembly has a transom plate and a pair of spacing brackets with jack plate rails. What is a Jack Plate? Similar to a setback, a jack plates also add weight and some distance (typically much less) between the engine and transom, but the primary goal of this feature is to raise and lower the engine within the water. installation instructions and owner's manual 7 engine side of jackplate insert engine bolts and washers (supplied prior to mounting jackplate to transom additional bolts per engine manufacturer's recommendation. For sure you still remember our post last time about CMC Jack Plate. 1 " is to high Kicker brackets are for small engines and the 1 U have is over a 100+ lbs. A jackplate is a specially designed mounting bracket for an outboard motor that lets you to raise or lower the motor vertically. The plate utilizes hydraulic pressure to maneuver place at the control of this operator. 1-48 of 155 results for "jack plates for outboard motors" Skip to main search results Amazon Prime. The CMC Manual Jack Plate 65012 comes with a screw in the center of the structure to allow you to use a 1-1/8" socket with a racket. Outboard Fuel Pump For Johnson Evinrude 20hp 25hp 28hp 30hp 33hp 35hp 40hp 45hp.



You should get the right size shaft for the boat. If you add a jack plate generally you would be raising the motor. Raising the motor provides less drag on the boat and lower unit, and directs the motor's thrust parallel to the water. It is a simple add-on to the mount. Re: Using jacker plate to lower instead of raise outboard on transom the motor is a J40TEEOD it has the motor mount that hooks over the transom and clamps with a scew deal. All parts fit together well. Engine is being stored at Shawmere Cottages in Lyndhurst, Ontario. Re: Outboard Brackets and Jack plates The Midnight is an 1987 with 1999 Engines bought new in 2001 with upgrades and 6 year warranties. 00 Honda Outboard Bf115 Bf130 Lower Unit 25 Inch 1428r Remanufactured Yamaha - $1,815. Are sterndrive and outboard support devices really needed while towing? And if so, what are the best devices to use? For the answers, we asked Mercury Marine’s chief engineer for outboard midsections, Bob Stuber, who offers these insights. Its incredibly simple design assures you of Precise, Smooth Adjustments Each Time, Every Time for your outboard powered rig. Porta’s primary product is the unique Porta Hydraulic Transom Bracket , a one of a kind product in terms of vertical travel and number of motors accommodated. snug it up. 851, 880686t56 Motor - $2,200. With a jack plate, you can raise the engine higher in the water column, thereby decreasing drag. Hydraulic Jack Plates; Hydraulic Power Unit; Jack Plate Parts and Accessories; Manual Jack Plates; SE Sport Hydrofoil; Set Back Brackets; Skeg Protectors & Nose Cones; Smart Tabs; Sport Tabs with Control; Stabilizers; Trim Tab Controls; Trim Tabs; Propellers. Outboard Jack Plate is a popular item and there are a lot of on-line online specialty shops that are making it available. We have the largest selection. Rather than the stern "squatting down" in the water initially, the way it would with a standard engine mount and the engine trimmed up, the stern moves forward as the jack plate allows the engine's thrust to work, keeping the prop high enough to miss the bottom.



BRAND NEW- MJ-1 Mini-Jacker by TH Marine •Cast aluminum •Designed for clamp-on mount outboard motors up to 35 HP. After you install it put your boat on level ground and trim your motor until it is also level. The jack is an simple add on mount which enables your outboard engine trip to easily fix and down. Offered in 4″, 6″, 8″, 10″, 12″ and 14″ setbacks, Bob's Jack plates offer 1 piece design, unlike competitors that require setback spacers to achieve the proper setback. The maximum speed (right side vertical axis of the chart) would move to the left. The kickup portion of the assembly is chained to prevent over rotation of the outboard when a submerged object is struck. with two cylinder powerheads. 95 SEASTAR Outboard Jack Plate 10" Set Back Up to 300HP Mercury Yamaha Suzk JP5100R. I bought a Yamaha proped longshaft outboard (20" shaft) and am planning to replace the bottom end with a Outboard Jets lower unit. CMC is rated up to a 130hp. The Rapid Jack is available in setbacks ranging from 4" to 15" and is available in the heavier duty Magnum series. Boat Parts and Accessories Store. Competitive prices of Outboard Jack Plate and other similar products. Browse an expansive array of outboard jack plate plans in stock now. Most competitive brands can only be adjusted from the top. Porta Hydraulic Transom Bracket and Jack Plate Combination. Fits top bolt pattern of outboard (Lower bolt plate also. Shop 8 Outboard online!. Our innovative high tech engineered polymer rod and slot lifting design guarantees trouble free action.



It's an all-purpose beast that will change everything you thought you knew about boating in extreme conditions. The boat has a 4" drop transom, wich means it drops 4" inches from the sides. Obviously it helps to know approximately how high you need to go. Here is a quick video on how to Manually lift or lower your outboard engine. Jack Plates - Hydraulic, Manual, Kicker, Tilt and trim, etc Jack Plates, Hydraulic, Action, Manual, for engines of all sizes. With the Porta Hydraulic Transom Bracket you get both - the setback, with its advantages, and the vertical movement range - of 12" to 24" - much more than is offered by any. If you add a jack plate generally you would be raising the motor. The jack plate comprises a motor lift and a jack plate mounting assembly. A lubricant sump is positioned beneath the engine and oil is returned to the sump through a drain opening in a spacer plate that separates the eng. By eliminating water drag at take off and acting as a trim tab, HOT SHOT allows boats to plane 2 to 3 seconds faster. How to adjust a manual jackplate, slidemaster, bass boat performance. For instance if you have an Outrage-18 with a 14-degree transom angle, and your jack plate has a 14-degree positive trim angle to compensate for the transom angle, you will need to lower the jack plate 5 inches to come 'back to base', ie, the anti cavitation plate is level with the lowest transom point. Find Outboard Jack Plate In Stock Now. Mercury outboard lower unit parts for 18XD, 20 and 25 hp. We have boat engine parts, inboard engines, outboard engines, lower units, and stern drives from the brands you know, love, and trust: Mercury, Suzuki, Mazda, Volvo Penta, Tracker, Yamaha, Evinrude, and others. Yamaha four-stroke outboards (and the Yamaha two-stroke V MAX® Series 2) come standard with a three-year limited warranty for pleasure use.



Step 4: Select the Model of your engine. measure from the bottom of the running pad on the boat then to the center of your prop shaft a good starting point is to have the center of your prop shaft about 3 3/8 inches lower then your pad. Re: Transom Too High for Outboard Anything you cut off the top of the transom frame can be put back on under the cut. Find slow speed jack plates available for purchase now online. The joys of my first boat start,I have a 18'5 key west bay/reef with 4 stroke yamaha,powerpole,trolling motor and my Jack plate is stuck all the way up. Unfollow outboard jack plate to stop getting updates on your eBay feed. Raising the motor actually lifts the boat out of the water, enabling it to move faster. Shop with confidence. A lubricant sump is positioned beneath the engine and oil is returned to the sump through a drain opening in a spacer plate that separates the eng. Brand New SeaStar 10" set back Manual Jack Plate - Part #JP1100SS Only taken out of box for pictures! Asking $400 OBO Shipping will be additional, and at buyer’s expense. Because this is home made, there is no guarantee that another home-made jack plate, even if the same design, will act the. The jack plate has several uses, most involving shallow water operation. This jack plate has a slot adjustment of 6" to move your outboard up and down so. Neutral trim occurs when the motor is parallel to the stern. Install the propeller drive splash plate a the bottom of the motor mount slides, using 2-1/4-20 X ½" bolts and ¼ X 1" washers. A rotational force applied to the central bolt will move the lower plate. Outboard Motor Accessories lower engine RPM. Find Outboard Jack Plate and save. Outboard jack plate transom shims(US $48. The heavy duty bracket is designed for outboards up to 135hp or 350 pounds and it maximizes lifting power (even greater than the outboards tilt range), and it also allows for increased tuck-under to get heavy boats on plane quickly.



Mrspalmreader Ventilation Plate Outboard best photo gallery What Does A Hydrofoil Do On An Outboard Motor Impremedianet. It's like a wish list of best-in-breed features, seamlessly integrated into a single package - a powerful, rugged, high-performance engine that will change the market forever. • New high speed hydraulic actuator. The motor lift has a pair of bearings that are interlocked to a lift plate. 73 results for outboard jack plate Save outboard jack plate to get e-mail alerts and updates on your eBay Feed. Lower Mounting Setting the engine lower (deeper in the water) (Figure 7-7) tends to: 1. Porta Hydraulic Transom Bracket and Jack Plate Combination. Shop with confidence. Simply click on the schematic below and select the parts you need to repair your jack plate. What is a Jack Plate? Similar to a setback, a jack plates also add weight and some distance (typically much less) between the engine and transom, but the primary goal of this feature is to raise and lower the engine within the water. A jack plate enables your outboard to provide optimum performance in shallow water. Proudly made in the USA, we want to take a look at some of the unique products that come out of the Bob's Machine factory in Florida and document a. Unfollow outboard jack plate to stop getting updates on your eBay Feed. 1-48 of 155 results for "jack plates for outboard motors" Skip to main search results Amazon Prime. Stainless steel bolts. Essentially, jack plates lift your motor higher out of the water. Evinrude Johnson Outboard Lower Unit 115 Hp 1979 Long Shaft P 389819 Works. The Rapid Jack from Hydro Dynamics is an innovative jack plate design that uses a ratcheting mechanism to lift or lower your outboard motor.



Fitting low water pick up to outboard engine If this is your first visit, be sure to check out the FAQ by clicking the link above. Outboard Jack Plate is a popular item and there are a lot of on-line online specialty shops that are making it available. I have never seen a jack plate to lower the motor they are designed to lift the motor out of the water more. A correct conventional installation would generally place the ant ventilation plate on many engines about even with the boat bottom when the engine propeller shaft is parallel to the boat bottom (Figures 7-8 and 7-11). Jack Plates are the perfect solution for long shaft engines with a short shaft transom! The engine side holes of the Jack Plate are drilled 1. Re: Single outboard for a catamaran? The centrally mounted 60hp outboard on my 40' sailing catamaran would lose it's grip on the water quite often before I added a stabilizer or whale tail. • Aesthetically matched to SeaStar™ steering cylinders. When switching to the jet foot on an outboard you typically have to remove and remount the engine because of the differences in lower unit heights. Seastar Outboard. OUTBOARD ENGINE TRANSOM Wedges set ALL Outboard Brands 4-Bolt Patterns - $99. Hydraulic Jack Plate. We have the largest selection. THAT jack plate is made with a place for the clamp to fit and then drill holes at bottom for lower bolts. The motor lift has a pair of bearings that are interlocked to a lift plate. Question for you mud motor guys. 00 Bob's Machine Shop Action Series Jack Plate 6 Setback Outboard 100-106010. used jackplate.



Because this is home made, there is no guarantee that another home-made jack plate, even if the same design, will act the. If not the lower will be 12-15" deep in the water. Th Marine Atlas Hd Hydraulic Jack Plate 14 Set Back Mercury 350 400r Ahj-14vhd. Before you go out and buy yourself a Jack Plate, consult your dealer to see what the transom of your boat will tolerate and if your warranty allows adding a J/Plate. Best Answer: The jack plate is for raising the engine and to lower the engine it will cause the engine to be lower that the transom and controls and steering will have issues when tilting the engine if it will tilt with out hitting the transom. What experiences have you had with jack plates, hydraulic and manual? I have several issues mounting my Evinrude 90, 20" shaft on my Panga. Have a friend raise and lower the trailer dolly jack until the running surface is level. Choosing a Short, Long, or Extra Long Shaft Outboard Motors. Then you have a button attached to the wheel or throttle that you hit to raise the outboard once you're up on plane. Make things even better with free shipping in some cases. Installing the jack plate on your boat is a. Others may be more difficult. The wonderful point is that your web search brought you to our internet site and while we cherish your visit, we wish to reveal you precisely just what you are searching for which is Outboard Jack Plate. JACK PLATE: Setback,- "High performance strength design jacking plate meets the strenuous requirements of the latest high performance outboards such as the the OMC Ficht, Mercury Optimax and Yamaha 3. jack-plate. with a tunnel hull; the jack plate will be worth its weight in gold for running shallow. Re: Q; Raise the Jack Plate or Lower the Jack plate? Post by Oldschool » Mon Apr 21, 2008 11:07 pm ED, the jack plate moves the engine back away from the transom and that changes the planning pivot point to increase the length of the hull and gives the prop more leverage to lift the bow.



My Keywest required removing the motor to fit the rod in. Unfollow outboard jack plate to stop getting updates on your eBay feed. bolts holding the vertical support members of the splash plate assembly to the transom mount. Porta’s primary product is the unique Porta Hydraulic Transom Bracket , a one of a kind product in terms of vertical travel and number of motors accommodated. that is 9 " taller than my 25. this should get you in the ball park. Peter's estimates of speed gain are very low. Hydraulic Jack Plates 0-627HP (30). Essentially, jack plates lift your motor higher out of the water. It gets the cavitation plate on the lower unit back down to the bottom of the boat where it needs to be. Bob's Mini Camo Hydraulic Jack Plate. remove the trim tab (scribe a mark across the edge so you can get it back like it was). What is a Jack Plate? Similar to a setback, a jack plates also add weight and some distance (typically much less) between the engine and transom, but the primary goal of this feature is to raise and lower the engine within the water. With a jack plate, you can raise the engine higher in the water column, thereby decreasing drag. Fooling around with a lower unit that will stick 5" deeper into the water without modifications to the boat or add-ons like a jack plate are just not worth it, especially since I assume that the boat is reasonably small due to the 15" transom. Would a jack plate work to lower a motor with a 21" shaft low enough? Problem will be that your power head will be awfully close to the water line. The 17" prop may work, but a 16" should also be tried. Jack Plate To Lower Outboard.