Another Set Back Question...

[croSSed]

Hi S & F!
Please see the attached pics for my present set up. Hope they are helpful in analyzing the issue illustrated below.

My current set up does not allow me to raise the engine any further than the propshaft being about 3" below the pad. All the way down the top hole of the L/U is even with the pad. My boat has a flat transom (no step for the pad) and I have about 7" of set back presently. With the jack plate all the way down the top hole of the lower is about even with the pad. The jack plate is as high as it will go on the transom, and the engine is as high as it will go on the plate. I do have one option that will not cost me any $$ presently. I have a manual CMC 5.5" plate that I can add to get more height when I want to go faster. I am concerned about a couple of things:
1.) What effect will effectively doubling my set back potentially have on my boat's overall performance?
2.) Will the extra strain on the transom, jack plates, etc., of adding a second jack plate be too detrimental to attempt?

I'd like to try some different props designed to run at or near the surface and add more ability for my "fishing motor" to pull water in even at heights that are certainly above the stock side water intake holes. I hope I'm making sense. REALLY what I'd like to do is have about 7" of vertical travel rather than the present 5". Thanks for any thoughts.

[croSSed]

Couple more pics...

[croSSed]

And more....

[croSSed]

One more....

[200VEGAS]

what kinda boat?you will need a low water pick up type lower or put one one yours.
it will put more strain on those top mounts if you add the extra plate. it will also push harder on the lower transom. transom is good, right? take some pics of the whole rig. 11" of setback works well on a lot of boats. i run 12" on mine. it will balance on the rear and carry the bow better with the additional setback. especially when you carry passengers

[croSSed]

It is a CeeBee Avenger Mach II. I've attached a pic of the whole boat.

[Mr. Demeanor]

The further back you go (more setback) the higher the engine needs to be mounted which is the opposite of what you need.

[2.5_stoker]

i think youre better off buying a propper set back bracket/haudraulic transom vs. stacking 2 together...also as mentioned you'll need low water pick-ups, solid motor mounts (if you dont already have them) and a torque tab....if it were me id run it the way it is till you have the stuff to properly set it up...thats just me though....good luck on the speed quest

shaun

[geezer1]

croSSed... I'm not an expert, by any means, but will offer some analytical observations based on your pictures. If that is a long shaft engine, you may want to consider changing it to a short shaft. CMC makes extensions to elevate the motor higher than the standard bracket. You might want to look into that. I hope that's helpful. Geezer.

[200VEGAS]

i wonder if it has the lift of the cmc. maybe cause it is an allison plate, it doesnt have 5.5 of lift. maybe you could drill some new holes in the cmc were it attachs to the boat

[croSSed]

Thanks for all the suggestions. I really don't want more set-back as I look at my rig. I just wish it had another 3" of up travel. I could drill more holes and raise the plate on the transom, but I want the "down" position of the rig to be where it presently is. Any higher and my High Five wants to let go in turns. My "speed" prop holds just fine (26P Laser II) no matter the height.
Short shaft? I've priced them. Ouch. Too much $$ for the rig I'm using, IMHO.
I wonder if I could have the channels in the lift plate machined for more lift. I have to talk w/ CMC about that....

[pyro]

Raise the plate mounting, and replace that highfive with a Trophy Plus-- You won't need to bury it deep anymore.

Solid mounts will cure any handling issues.

Very handsome 150XR2 you've got there.

[croSSed]

Raise the plate mounting, and replace that highfive with a Trophy Plus-- You won't need to bury it deep anymore.

Solid mounts will cure any handling issues.

Very handsome 150XR2 you've got there.

Yeah, I really scored on the XR2. I'll tell you the story some time. Short story is I swapped my also very handsome '87 I6 115 for this XR2 with no money out of pocket. That deal also included acquiring my SeaStar Pro hydraulic steering which basically ended up being free.
I have solid mounts, and yes, they completely cleaned up the handling at high speed.
I am very hesitant to purchase a Trophy. I've tried a couple, and with the exception of a Mercury Chopper, the 2 Trophy's I've tried had the WORST hole shot of any prop I've ever used. I once purchased an old style, large hub 25P Trophy and it was a complete dog. I lost 4 mph on top end compared to my 26P Laser II, lost about 400 rpm, and it had no chance of pulling me up on a slalom ski. The only good thing I can say about that prop is that it made the boat handle like a well tuned Corvette in turns. Otherwise... bleh... I'd like to be able to try a couple small hub Trophys of different pitches and see then.

[geezer1]

croSSed.. I did a swap for a short shaft set-up. Just asked around, two guys responded, I took the best of the two. Didn't cost me anything. You'd be surprised at the number of people wanting a long shaft set-up. Should be plenty up there in Washington on the coast... Geezer.

[croSSed]

I would agree there are probably several I6 shorty's available, - I sold an engine with one - but a 15" mid for a V6? I think they are harder to come by, at least at a price that isn't prohibitive.

[2.5_stoker]

the trophy is a good all around prop...what we do is run a couple different props we found a 25 shooter that runs really well as a ski prop but when its time to go fast the 27 srx gets put on.....a lot of the big top end wheels will be sluggish out of the hole but its all give and take...if you get the motor raised id give that chopper another try

[2.5_stoker]

i guess it all depends on what you want to do with the boat....there isnt one prop that does it all perfect so to me it isnt that big of a deal to change a prop out while were on the lake instead of sticking whith a prop that does everything okay

[croSSed]

i guess it all depends on what you want to do with the boat....there isnt one prop that does it all perfect so to me it isnt that big of a deal to change a prop out while were on the lake instead of sticking whith a prop that does everything okay

I agree with this totally; I do it all the time. If I'm cruising w/ fam, skiing, tubing, etc., 23P High Five. Time to go fast, 26P Laser II. Since this boat as it is currently set-up GPS's at 72.5 mph with the Laser II, I KNOW there is more speed to be had: Raise it, and use a better speed prop. I'm currently looking at a Spinelli 3 blade 27P....

[200VEGAS]

small hub trophy might be the ticket

[croSSed]

small hub trophy might be the ticket

Just wish I could try one before I buy.
I found something out the other day. My jackplate is an ALLISON ONLY plate made by CMC that only has 3" of vertical travel, while CMC's regular PL-65 hydraulic plate has 5". There's part of my prob right there. Gonna call CMC tomorrow and see what can be done.

[200VEGAS]

yea, probably cause allison is set up high from factory for surfacing props. the allison plate is probably built more to be as light as possible, instead of a universal plate like the cmc to help as many applications as possible