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ContinuousWave: Whaler Performance
Setting Up Jack Plate on Outrage 19
|Author||Topic: Setting Up Jack Plate on Outrage 19|
posted 06-04-2004 06:42 PM ET (US)
I bought a used CMC Power Tilt *manual* jack plate for my 1990 Outrage 19 with 115 Johnson. I figured installing one of these would give me all of the benefits of a Jack Plate and also not require me to drill new holes in the transom to raise the engine (original installation incorporated the engine's blind holes...) The prop is a 4 blade Stilleto. 13 3/4 x 15.
I bought the Jack Plate used on Ebay and it has no instructions.
You can see a picture here (scroll through the T-top pics):
I know how to bolt it to the transom and the engine to the Plate, but I really need some ideas on what holes to use and, most specifically, how far above the bottom of the keel should I set the Cavitation plate. (1 1/2 inches?). I will fiddle with it after I have an initial setup, but there are numerous holes that I could use and the selection of the right holes will determine my range of vertical movement.
As a general rule, should I try to bolt the Jack plate to the transom such that the the top of the plate is in line with the top of the transom?
Any and all ideas are greatly appreciated!
posted 06-05-2004 09:17 AM ET (US)
I would position the plate on the transom so that the minimum amount of lift was not excessive. You don't want to be in a situation where the lowest mounting possible for the engine results in it being too high. It is typical that a plate like this incorporates and inch or two of lift of the engine even at the lowest point of adjustment.
It would seem likely that the existing upper holes drilled in the transom ought to match up with pre-drilled holes in the plate. It will be the lower set of holes that will probably have to be re-drilled in the plate to match the existing set of lower holes you now have in your transom. These lower holes, as you mention, were drilled to match an elevated single mounting hole set on the original engine installation (the "blind hole").
posted 06-05-2004 09:33 AM ET (US)
What you say makes sense and means that I will have to mount the Jack Plate to the Transom such that the top of the plate will be higher than the top of the transom.
Well, I'm off to give it a shot. I'll report the results.
posted 06-06-2004 09:58 AM ET (US)
Ed, I am quite surprised at your response. My interpretation of what I said would lead me to believe that mounting the plate that high would not be consistent with my advice.
posted 06-07-2004 12:33 PM ET (US)
I cannot find this model on CMC's web site:
This leads me to believe that your model has been discontinued. In addition, from the picture you posted,
I do not believe this is a CMC Power Tilt at all, but more likely an early version of the two piece adjustable manual set back plate. (Please note that the smaller bracket mounts to the transom, NOT the larger.) From the photograph, it appears that the transom side of the set back brackets do not have the correct "blind" holes pre-drilled. Therefore, you will have to mount the engine to the two pieces, then mount the set back brackets to the engine using the HIGHEST two upper mounting holes on the bracket. (Make sure the verticle adjustments on either side of the bracket are in EXACTLY the same position.) Then run an awl through the interior blind holes and mark the position of the blind holes on the bracket. Repeat this procedure for the remaining 3 (upper) mounting holes, relocating the bracket on the transom each time. When you are finished, drill the LOWEST corresponding blind hole marks that are reasonably clear of the lower sliding holes, and mount it to your transom. Now, your set back brackets are mounted as high as possible on the transom, and you can use the verticle adjustments and engine mounting adjustments to achieve maximum (or minimum) height.
posted 06-07-2004 05:18 PM ET (US)
Sorry, this should read:
I do not believe this is a CMC Power Tilt at all, but more likely an early version of the two piece adjustable manual set back plate. (Please note that the smaller bracket mounts to the transom, NOT the larger.) From the photograph, it appears that the transom side of the set back brackets do not have the correct "blind" holes pre-drilled. Therefore, you will have to mount the engine to the two pieces, then mount the set back brackets to the TRANSOM using the HIGHEST two upper mounting holes on the bracket. (Make sure the verticle adjustments on either side of the bracket are in EXACTLY the same position.) Then run an awl through the interior blind holes and mark the position of the blind holes on the bracket. Repeat this procedure for the remaining 3 (upper) mounting holes, relocating the bracket on the transom each time. When you are finished, drill the LOWEST corresponding blind hole marks that are reasonably clear of the lower sliding holes, and mount it to your transom. Now, your set back brackets are mounted as high as possible on the transom, and you can use the verticle adjustments and engine mounting adjustments to achieve maximum (or minimum) height.
posted 06-07-2004 08:24 PM ET (US)
A most sincere thanks to Jim and Ratherwhalering for their advice.
Using this information learned from this website I mounted the vertically adjustable transom jack to my 1990 Outrage 19 with great success and fabulous results. Note, the particular model I purchased in not considered by its manufacturer, dba Cooks Manufacturing (aka CMC), as a true transom jack as it has no mechanical (electro-hydraulic or screw drive) provision for adjustment "on the fly". Rather, this 2-piece setback bracket has the ability to have its adjustments made manually via floor jack, with 4 large bolts retaining the vertical positioning between the Transom Mount Plate and the Engine mount plate. (See pictures linked below)
This is how I did it:
- Got friend over to assist me in lifting the engine off the transom. We did this by lowering the motor and raising the trailer jack to the point when the engine's keel rested lightly on my garage floor. I them removed the 4 bolts that secure the engine to the transom. We then lifted the motor slightly to clear the transom completely. We then slid the engine to the starboard side of the stern. Heavy, but doable.
- With the proper new stainless bolts, washers and nylock nuts, I then mounted each side of the 2 Set Back pieces to the Transom, using only the 2 top holes that were pre-drilled by the original outboard rigger. I had to mount the transom side of teh setback plate high enough to clear the drain tubes on the outside of teh stern. I then attached the motor to the Set back plate by repositioning the motor behind the plate now attached to the transom and bolting the motor in place.
- The entire package was now being suspended by the 2 upper bolts installed through the upper holes in the transom. Everything was perfect as the 4 mounting bolts assembled to the motor's bracket and the transom set back had enabled the transom's lower bolt holes (originally drilled to be used in the engine's blind holes) on the transom side of the bracket to be perfectly aligned with a fresh, un-drilled 1/2 inch aluminum surface.
- I then inserted a 1/2 inch drill bit into the lower transom bolt holes, originally drilled to accept the outboard's blind holes, through the splash well and proceeded to drill a new hole into the set back bracket's transom plate. I installed the original bolts though the original hole in the transom and the new hole in the setback bracket and secured them with new nylock washers.
- I then made a preliminary vertical adjustment using a floor jack. I knew, by searching this site's archives, that many folks set their cavitation plates ~1 inch above the keel when the engine is bolted directly to the transom. So, knowing that the engine would be benefited by running in "cleaner" water as afforded by the 5 1/2 set back, I positioned the engine's cavitation plate to 2 1/4 inches above the bottom of the keel. We got lucky because this particular setting puts the engine in the middle of the adjustment range of the set back bracket, giving me plenty of tuning room.
Time for the water:
- In a word, wow. The boat could now hold plane at amazingly low speeds... I didn't have a GPS onboard, but the boat would hold plane at less than 3,000 rpm (in a salt-water river, flat calm)... This on an Outrage 18/19 with a 115 horsepower motor turning a 13 3/4 x 15 4 bladed Stainless propeller. The boat planed faster, despite the simultaneous removal of the engine's DoelFin. The boat felt softer in the 5-7 foot surf we were later pounding through (very confused water with tight tight moments between waves). The boat ran quieter as the motor was now outside of the boat's resonance cavity (the inner hull). There is a tremendous amount of new found space in the splashwell as the motor isn't hanging over half of it. Plus, sheesh, it just looks cool!
Here are some pictures. Please excuse the poor appearance of the boat.. I haven't cleaned up the hull yet.
posted 06-08-2004 09:10 AM ET (US)
I find this thread very interesting.
but this i know from being a boat rigger,
so a platform or setback plate of three feet would mean three inches of rise from the keel to the anti cavitation plate on the lower unit
posted 06-08-2004 01:50 PM ET (US)
Good job Ed, it looks like a solid job, done well.
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