Jackplate ?????

hey everyone. ok i have a early 70's SeaNymph and just picked up a Johnson 9.9. only problem is its a longshaft motor and i only have a 15 inch transom. i saw the Minijacker jackplate in BPS and i desided to make one at work it has a 3 inch rise and 4 inch setback just like the mini jacker. now when i put it on it seemed like it sucked the boat down into the water and when i was at WOT and let off this foot and a half wall of water was coming toward the transom and made me nervous as hell. i am 300 lbs and i know that has an effect on it but i have some trim adjustment im really not sure what to do. but honestly it seems to me better with out the plate. any ideas???

Re: Jackplate ?????

make a transom elevator, rather than a jack plate, it will move the weight back over the transom. as far as quick stops, they are not good on any boat. what year is the 9.9, that determines the amount of rise you need on the transom. is your motor a 20 inch leg or a 22 inch leg.

http://forums.iboats.com/showthread.php?t=200994

Transom elevator
you can either do a transom elevator or a jack plate. we are talking about a 10 hp, so a transom elevator is the right solution. it is taking 4 pieces of 1 1/4 inch aluminum angle, sold at home depot near the screws and nails. you put a 2x6 on top of your transom thru bolt it with 4 bolts, then thru bolt thru the transom. i would use 18 inch pieces of aluminum angle. so you need 4 pieces of angle and 10 3/8 bolts& nuts, 20 washers 10 lock washers. get it mounted set the motor and go boating, safely.

Re: Jackplate ?????

you would have been better off going with little or no set back.. and I dont know why you stopped at 3" of rise...if the motor is a loong shaft it is either a 20" or a 25"( for sailboats)( never heard of the 22" version myself)

you need to make the rise equal the difference in your motor's shaft length and the 15" of transom you have now.

3" was way short....

plus the setback actually allows you to go even higher than normal.....but that is another can of worms

good luck

bob

Re: Jackplate ?????

well i just tried to make it to the mini jackers specs. but i should have made it the full 5 inch. hindsight 20/20 ya know. thanks for you input has anyone mad a "transom elevator" if so please post pics for ideas plz. im not quite sure i understand the instructions in the other post. it is a 20inch motor shaft. whats the easiest way to get it up in the air.

Re: Jackplate ?????

the mini jack plate has those dimensions, because it is used to set the motor back and when you do that you can ALSO rise it up...to have less motor under water because the water in the boats wake rises up..... so guys go back with the motor ..sooooo they can raise it up....but it is usually small amounts.

it is not to make up the difference between a short shaft and a long shaft...which is usually about 5"...15 to 20...and 20" to 25"


I guess on rare occasions someone might want to put a sailboat version kicker( super long shaft) onto a short shaft utility boat.

you just need to go up..and you dont need something real intricate...because your 9.9 is most likely has a clamp on bracket.

just bolt a big piece of aluminum onto the transom and have it rise 5" above the current transom..

you only need to be about an inch or two wider than your bolt pattern used to attach the plate to the transom( many boats already have bolt hoels)

you could use a 1/2" thick piece of aluminum and up at the top bolt another 1" thick x 2" high piece onto it...(the thicker top is for the clamps of the motor bracket)..the 1/2" aluminum is strong enough for a 9.9 hp!!

basically a 1/2" setback with the rise you need!!!

two pieces of aluminum!!!! and maybe 6-8 bolts and nuts.

of course the plate that Tashasdady suggest is probably adjustable..... which might help you fine tune your setup after you mount the motor..

good luck

bob

Re: Jackplate ?????

here:


also look at this. http://forums.iboats.com/showthread.php?t=319237&highlight=transom+elevator

Re: Jackplate ?????

One thing you could do, since you apparently have the capability to bend metal, would be to breaka piece of aluminum (18ga maybe) around a 2x6. Basically make a channel if you will. It would be the width of the 2x6 and about 7 or 8 inches high. Make a "U". Then keep the 2x6 in there and bolt it to the transom. One piece of aluminum, one 2x6x12", four bolts. Clamp it on and go!

Good luck!

Re: Jackplate ?????

too bad I don't live near you. I have a Evinrude short shaft and would trade for a similar condition long shaft.

That might be your best bet - try to find a local trade. Long shafts in my experience are more rare and sought after and you might be able to make this much simpler.

Re: Jackplate ?????

d.boat said:

too bad I don't live near you. I have a Evinrude short shaft and would trade for a similar condition long shaft.

That might be your best bet - try to find a local trade. Long shafts in my experience are more rare and sought after and you might be able to make this much simpler.

Click to expand...

1985 Johnson 9.9 longshaft 20 inch electric start anyone??????? lol

Re: Jackplate ?????

I have a queston on the jack plate thing

I have a 82 18' Bomber and I saw the jack plates in Overtons and was wondering if you can replace an I/O with one??
I would like to make more room in the boat if I can and getting rid of the 485 Merc would be my best option for that.
The thing I don't know is if would be the best thing to do for the boat?

Sorry for the hi-jack.

Re: Jackplate ?????

youd wat to make sure the transom is beefy enough to hold the weight of the outboard hanging on it.... for one

then youd have to make sure you got a wedge mounted under the jack plate to give you that 10-12 degree angle that most boats have on the transom..

so you can keep the bow down..

good luck

bob

Re: Jackplate ?????

After pricing what the 3' X 3' space would cost me I could buy a new car
Thanks for the input.

Re: Jackplate ?????

Tahasdaddy
on your drawing above what size alum. angle and thickness did you use?
i have a 2010 merc 25 EFI i need to raise on the back of a 12.5 footer inflatable
any drawbacks using your elevator on an inflatable?
thank you for any response.