My 12' hydro and advice needed for setup.

[MN1]

Some of that sounds OK but
#1 - Yes fix the skeg
#2 - Yes it would help
#3 - No, raising the motor that high can be done but you will need a higher pitch prop than 23". And you have to keep an eye on water pressure.If you had the cavitation plate 3 to 4 inches above the bottom, that would be plenty for playing around the lake. But you would still need a race prop when you start raising the motor.
#4 - Only if you want to go slower.
#5 - Sure try it. Or if you can find an old elephant ear 2 blade.

Maybe he means solid engine mounts along with the steering.
This place sells some stuff http://www.bobsmachine.com/

Mark N

[ricochet112]

Hi Guys
Hey went to the river this afternoon and lot of power boat guys around so asked some advice from them.
1. The skeg on the bottom is partly broken off, the guys said get it fixed as it can make the boat squirrly on the rear.
2. Get rid of the rack and pinion and get a good cable steering system.
3. Raise the engine so that the center portion of the bulb sticking out is even with the bottom.
4. Conflicting report here, another guy pulls in and said you ought to try and lower the engine so it is riding more on the diffusion plate. Hmm.
5. Get a chopper prop. Yikes more money..

I meet the guys out in the river basin and we yaked a bit and then they said they would keep a eye on me in case I dumped it if I wanted to make a power run. I had installed the 23 pitch on before I got there to try it out and it sure makes the boat scoot too. I made a dash over to the leeward side of the river were it was fairly calm doing 50mph, turned it around and said to myself "well here we go", got it up on plane then punched it and it got up to 62mph real quick and still had some throttle left and I chickened out as I was starting to get into the choppy stuff. When backing down the boat went into one hell of a wobble on the front end. But came out of it okay and a little bit scared for sure. The guy who informed me about raising the engine said that the engine is not stable enough and causing the swing when slowing down and to see if I can make the engine hard so that it will not swing. Learning somethings I do believe..
Jimmy

You are so over powered for the boat, you'll have to find a happy medium.
Lowering the motor so the cavitation plate is level with the bottom will slow you down a couple of MPH, but the trade off in handling will be worth it, IMO. In fact you may be able to drive it faster because you will feel more comfortable IF it handles better. It's just too much motor for that size of boat. And this is taking into consideration that the bottom is flat, square and it has no twists or other problems. No amount of set up tweaks will fix that.

[Jimmy70]

Thanks for the feed back guys. These guys on the river were running some 19' boats also so I am sure they are a lot more safer than I am but they seem to want to help out so I got big ears and open to comments from anyone. I am going to pop off the 115 and slap on the little 40 and see what that will do for me. Might as well since it is just hanging there for right now and not that much trouble to shift it over.
Jimmy

[ryan_4z]

Another thing to consider. Without any airtraps behind the sponsons, the front of the boat will ride higher, and the back of the boat will be buried in the water. You might want to trim the motor under just a touch more to keep the front down a little bit. You could also make the sponsons shallower, which would probably be the better option, but that would obviously be more work. If you trim the motor under be carful about the back end breaking loose. You could keep this from happening by adding a couple of fins to the edges of the bottom at the aft end.

[Jimmy70]

We had a great day yesterday so l made a river run to check out the 23 pitch prop. Interestingly enough there were several high power speed boats that showed up just for some lake cruising and they all came running over to check out my little 12' boat. They started popping ideas so made some mental notes of them to take care of or look into later.

One of the stupid mistakes that I made is not having the engine mounted hard to the transom with a transom pin so now I know what is causing the bow to jump around on me when slowing down, when I back off the throttle the water pressure is pushing the engine back and that causes bow lift real quick. It is a wonder I didn't do a good number on myself.

Anyway two of the power boat guys wanted to know if I wanted to crank it out and I said yes but come over to the leeward side of the river and I will give it a go. Well I curised down to the turn around at 55mph, made my turn around and booted it a good one, I was doing 62mph in nothing flat and I buried the speedometer as it only goes to 60, I was using the GPS for correct speed measurement. But when I started backing down then the boat started the wobble again and pretty bad too, so pulled the trottle back and got out of that one okay. So I had enough of that for the day and then got to thinking about what I thought was okay but sure was not. As I have some hydraulic lift cyl. on the unit I was thinking they would be oil locked and not move, NOT TRUE. Hell they only lift the engine and not for trim setup. Brain Locked again but now I know what I have to do to fix the kick back.
Anyway I enjoyed the ride even if it scared the crap out of me on the shutdown. Live and learn but not the hardway.
Jimmy

[ricochet112]

Your hydraulic rams look home made. They look like standard manual rams. Mercury's rams are larger and have 2 hoses going to each cylinder.
If you have reverse lock hooks, get a tilt pin and try it that way.
Having the motor trail out on you at speed would be quite a thrill http://cgi.ebay.com/ebaymotors/Mercu...WDVWQQtcZphoto

[Jimmy70]

Believe me it was scary for a couple seconds, I begin to think I may be to old for this kind of stuff, but hey life isn't just setting home watching TV like a lot of folks do. I thank you for the post and thought about bidding on them but again I would need a pump so that would be anothr 3-4 hundred. A pin will do for now.
Jimmy

[79-0-DMH-Ron]

trim and tilt

Hello Jimmy,

Cool looking setup!
FYI....I just wanted to let you know my brother owns those hyd. rams on ebay. right now they are at $66 and he has the pump which went to those hyd rams on ebay as well, it currently has a bid of $100 on it. It might cost less than you think to put trim and tilt on your rig. His Ebay store is wrightonmotors.

As was mentioned earlier i think a small air trap might help with geting the back end of your boat out of the water. I am not a boat builder by any means but i believe all modern hydro's have air traps, at leat all of mine did. As for raising your motor i wouldn't raise it much more if i remember the water pickup on those 115's was above the bullet on the unit. make sure that that is below the botom of the boat. Also that unit being as big as it is probably would have a tendency of blowing out the back end of the boat at speed if you were to raise it much more. if you have ever eperienced prop walking at speed it can be pretty scarry. Just an idea but if you were to add air traps to the botom of the boat, and and put the cavitation plate even with the botom of the boat and ran the engine parrell with the botom of the boat that might make it perform better. My .02

[Jimmy70]

Thanks for the feed back on the units. I have had no luck in trying to find some photos of air traps to see how they should be placed on the boat. I ordered a book from Jim Russel out of Canada so I am hoping for some info on them. I think for right now I am just going to go with a pin to hold the motor down and see how that works out. The cavitation plate is just about 3/4" above the bottom of the boat and I am not to crazy about trying to move the engine up as suggested by a couple of these hot rodders. Like you mentioned the water pickups would have to modified or have some way to get water into the engine. So far I haven't had any complaints about it running smooth on the water it is when I powered down that scared me with the engine kicking back and causing the wobbling, should have know better but with the pin locking the motor down I think that will take care of that problem.
Just wondering if any of you have had experience with the hydrofoils that you attach to the cavitation plate???? When I was at the drag boat races I seen that all of those boats had them on their boats. Course when they were power running all that was in the water was those plates and the prop.
So if any of you have some photos, hand drawings of some air traps and thoughts would you please post them for me.
Thanks for the info from all of you.
Jimmy

[krazy karl]

Kill Switch

As some of the guys mentioned here about installing a kill switch, a must, I would also install some sort of deadmans throttle. If you start to get into trouble with that lever control you are going to be lucky to be able to react quickly enough to get yourself out of trouble. Like the other guys have said, you've got an awful lot of motor on that boat, be careful. Hitting the water at 60 is no fun, I've done it and I am "only" 62. lol Most of all good luck and have fun.
kk

[Bill Huson]

nix on the "hydrofoils"

called Whale tails. The purpose they serve is to get a boat up on plane faster, great idea for a slug boat that drags butt while trying to launch over the hump. I'm guessing more junk in the water back on the engine lower unit would cause your sketchy rig problems.

Like others have mentioned --> deadman throttle is a MUST, and so is a working kill switch and tether attached to your bod.

[dcrummett]

Jimmy, if you'll notice, most racing outboards are tied with rope to the transom to prevent backwards movement. Tis a problem when the motor (one of three contacts with the water) is up and you have only sponsons, the bow, the stern, your head over and over and over to control your boat.

Dan
O-49

[Fast Jack]

Trim pump

If you want a trim pump I have one with hoses and probibly have a wiring harness for it. sell cheap or trade . Shawn

[Don]

Hi , where are you in N.C. ? I am an old boat racer and live in Belhaven, N.C. I have plenty of stuff for 115 mercs and racing. dondsj5z@gotricounty.com if you are any where near me,get in touch and we can talk set up's . Don 5-Z

[Jimmy70]

Hi Don
Live here in Bethel, north of Greenville. I would like to meet up and jabber with ya.
Jimmy