Jack plate performance

[lakelover]

This is essentially the same post I have over in the Restoration forum, so my apologies to the mods and others, but I'm about a click away from ordering a jack plate for my setup. I have had helpful suggestions in general on jack plates, but would like to know some specifics related to performance and handling before I order.

The boat is a 15? Starcraft Jet Star that weighs about 400+ lbs. with a 16" transom and the motor is a 200 lb. 50 hp long shaft Johnson. (The Jet Star has the 4 seats forward, back to back, not 2 in front and 2 in back like the Jet, so passenger weight would be more forward).

1) How does the setback of a jack plate affect the balance/performance of a boat? Use of the boat will be primarily cruising around with 2-4 people.

2) How does it affect getting up on plane?

3) Does a motor mounted that way add stress to the transom? (It seems to me, yes). Is it just not very appreciable with a 200 lb. motor set back about 4??

4) Are there advantages/disadvantages in terms of safety, handling, or performance?

I'm not interested in "high performance", just good performance and safety.

 

[BLU LUNCH]

Re: Jack plate performance

I running a jack plate on a Wellcraft V-20 because I have a 25 inch leg on the Mercury 150 and a 20 inch transom . What I have noticed is putting the boat on plane is effortless because you can tuck the motor in further than it mounted on the transom. You cant even tell its there, it handles great and no balance problems, nothing quirky to mention.............

 

[lakelover]

Re: Jack plate performance

Blu Lunch,

Thanks for the input, it's very helpful.

 

[Boss Hawg]

Re: Jack plate performance

I have a 10" on my 20' Ranger Bass Boat & planing is dang near instant
You have to work it tho

 

[BLU LUNCH]

Re: Jack plate performance

I have a 10" on my 20' Ranger Bass Boat & planing is dang near instant
You have to work it tho

Mine will plane in less than 2 boat lengths

 

[4JawChuck]

Re: Jack plate performance

I have a jackplate on my Tuffy also, its a 6". I bought it to tune the motor height to get the most speed out of the package. I picked up 3-4 mph just dialing in the engine height.

I didn't notice any difference in planing speed but trim at speed sure is better, the extra leverage of the motor off the transom means the motor doesn't need positive trim to fly the bow...there was speed gained from that alone.

However on your small motor you will likely see little difference and it probably won't be worth it. Put a 90-125 on the back of that puppy...then it would be worthwhile doing. Unless your going to repower soon with a bigger motor I would save your money.

 

[ddrieck]

Re: Jack plate performance

lakelover,
You can expect to see the following by using a jack plate with your 16'' transom and long shaft outboard.

- Increased speed, due to getting prop up out of the water, Less drag=more speed.

- Get on plane faster because the setback will get your prop out of ariated water. This allows the prop to bite hardere in clean water. Will also plane out faster due to the reduced drag from the leg being at the right height in relation to the keel.


- Increased handling: Your boat will act like it is longer than it is.

- Reduce or even illiminate porpusing; Setback allows you to tke advantge of a longer trim swing.

- There is some added stress to the transom but it will not be a problem if your transom is in very good shape. DO NOT install a Jack on a rotted or weak transom. That is just asking for trouble

Most of the forces applied will be at the top of the transom so if your do install a jack add a washer plate to the inside of the transom. This will spread out the forces and keep the bolts that hold the jack from trying to tear into the transom.

The major thing is to get a quality Jack Plate to start with. If you buy cheap, that is wat you get cheap.

With all that said, PM me and I can help you out

 

[lakelover]

Re: Jack plate performance

Thanks much for the detailed reply, just what I wanted to know. Plans include a plate on the inner/upper transom. I have absolutely no first hand experience with a jack plate. As mentioned, my purpose is so I can use the motor I bought, but better performance will be an added bonus.