Help with outboard positioning needed

[Footerbear]

Hi, I'm new here so forgive me but I'd best start at the beginning.:)

Last year, because I couldn't get a brand new Flightcraft Barefoot outboard boat in England I had a one off built based on the 20ft British built "Sportique XLS" Hull. Originally these boats are powered by Mercruiser type mid engine/ rear shaft prop and rudder. Sportique have been very helpfull and built the hull, basically with a flat Transom, reinforced to fit an outboard mounting bracket, and obviously reinforced the transom etc etc.

The boat is beautiful but I'm having trouble getting it to handle decently at speeds over 35 mph, which means I cant Barefoot with it at the moment because we need speeds up to 45 mph.

The beam is about 6foot 6 inches. The bottom of the boat hull at the front is a deep V with big negative chines, with the rear third pretty much flat bottomed, all the way across the Transom. The motor is a 225 HP Yamaha. The bracket I have at the moment gives a set back of about 12 inches, and an offset to Starboard of 1inch. I'm using a Quicksilver 19 pitch "High five" prop.

I think the bracket design is fundamentally flawed as it touches in the water and gives loads of spray. I am currently trying to get a tubular Gil Bracket or similair.

We have tried a hinged plate underneath the bracket, like a central trim tab, which reduces the spray, but I dont think its helping the handling or prop bite, which I'm really not happy with. As I run the boat at 35 mph it runs fairly level but feels like it wants to list one way or the other depending on slight steering deviations from straight ahead. If I then push the throttle down further the hull rolls to the port side and needs far too much "trim out" which only partially corrects this. Also, turning the steering and the boat seems to list onto the "wrong" side, I wouldn't mind if it turned flat, but it seems to dip the starboard side in the water when turning to port and vice versa. Also a lot of prop cavitation even in relatively leisurely turns at low throttle openings. If I drop the motor any more I get loads of spray as the cav plate is too low.

Any thoughts, theories, fixes, help and info will be gratefully absorbed, before I pull the engine off this weekend and strip off the motor bracket. As I said earlier, I think this is basically my problem, but I'm no expert. I think I need more offset too, say about 2 inches. Or have I got a more sinister problem of say the wrong hull shape, if so can the bottom be re -shaped to a different style using fibreglass or is this likely to just crack and fall off ???

:confused: :confused: :confused: :confused: :confused:

Dave

[gonzo]

It is the wrong hull for an outboard. It is turning outboard on the turn probably because the outboard makes it top heavy.

[lazeyjack]

the plate should be one inch above the run of the keel, and what is your bracket angle it should be 13 dgrees, you seem to know what you are doing, have you considered trim tabs? and do you have a photo?

[Footerbear]

Hi,

Thanks for your replies guys it's much appreciated :) Theres not much knowledge over here in the U.K. and most of my friends in the marine industry build and set up Race Boats, which is a totally different ball game.

Gonzo:- There are a couple of boats in our club which are Inboard Tournament style hulls running big Outboards on brackets, flat at the back, yet they dont roll over the "wrong way".... not sure what you mean by the wrong hull, and what can I do to make it handle better. Would low down ballast in the ski locker improve the top heavy situation ? Also why is it ok at 35 mph but gets unstable when I go faster, I would have thought it would get better ??

Unfortunately, I have spent nearly £15K (without the engine), having this boat built so its a bit of an expensive mistake to just junk the hull !! :( With hindsight I wish I'd bought a secondhand Flightcraft and re - fitted it, but over here in U.K. they are like "hens teeth". However, I did know it was a prototype and that some work to set it up may well be neccessary !!
Can I re-shape the underside with fibreglass if neccesary to get a shape similair to the Flightcraft at the back end, and if so how do I go about it? Fibre Glass layers and filler ? Is this likely to crack and fall off or would it be ok provided it is keyed in properly ?

Lazy Jack:- The back end of the hull is flat in front of the motor for about 2 ft then gets a progressively increasing V as you go forward to the bow. Do you mean an inch above the flat bit or do you mean get a long straight edge and run it from the V further forward, and set the cav plate an inch above this ??

Will get some photos this weekend, but I think the outboard is lower than you state at the moment. I have a new motor bracket coming, which is designed properly, i.e. it wont drag in the water, which will mean I should get the correct flow of water around the gearbox of the outboard, rather than all spray !! If I raised the outboard with the existing bracket the overheat buzzer came on because the lower part of the bracket was lower than the back of the boat......The guys who built it were very helpful but I think their a bit clue less !! They then supplied a plate to fit under the bracket, like a central trim tab, which cured the spray but there isnt enough adjustment left on the bracket to raise the engine any more. Also I'm not sure about having a plate immediately in front of the outboard, and flush with the bottom of the hull. I think it is possibly having an adverse effect on the handling and also the cavitation issue ?

Both of your thoughts on any of the above would be most welcome

Regards Dave

[footer Dave]

Footer Bear:

I know a guy who had a barefoot centurion that ran almost exactly as you described. He tried all sorts of fixes before going back to the manufacturer. They determined that the hull was warped ... turns out the hull was popped too early and left to finish curing out of the mold. I'm not saying that this is your problem, but you may want to examine the hull for good measure.

[Footerbear]

Thanks Footer Dave,

Since the post I have had a new engine bracket made to my own design which has allowed me more offset and to do away with the silly central plate idea. This has improved the situation a whole lot :) but it still isnt perfect.

I have noticed that the boat handles better when weight is in the back end, and also when I look over the back at say 35 mph + the engine definitely needs raising at least another set of holes. It is currently running 2" offset, maybe another half / one inch wouldn't hurt :confused:

Trouble is we moved April this year, re - locating to Scottish Highlands and I have so much building works on I don't get out in the boat much at the moment. Bit of a wind up really as we have a glass flat Loch (Lake) at the bottom of our land and I havent got a jetty in yet :(

Regards Dave

[footer Dave]

I wish I had the money to build a decent outboard barefoot waterski boat. All of the U.S. manufacturers have stopped making them ... but they won't sell their molds:mad: The best offering in the States right now is the Sanger DXII "Barefooter" (an inboard 20' LOA hull with 16 degree deadrise and 8' beam). Sanger used to make a very nice outboard hull, but stopped when California emmisions regulations caused the price of 2-stroke motors to skyrocket (Sanger is a California based manufacturer).

I currently ski (foot) about 3-4 times per week with a friend who has a flightcraft (2000 model year). Too bad Malibu no longer makes this boat ... it's one of the best footn' boats ever made! Below is a photo of his boat taken earlier this year. Although you'd be hard pressed to find one as well cared for as his, a few of them are still for sale here in the States. Have you ever taken a look at this site?

http://store.barefootcentral.com/index.asp?PageAction=VIEWCATS&Category=62

The Super extended pylon you see in the photo is brand new (custom made). We've been skiing with this device since late April/early March (notice the absence of foliage) and absolutely love it. It greatly reduces our weight on the water and even helps the boat run with a little more hull out of the water (with a footer in tow, of course). We've noticed slightly improved fuel economy as a result! But the best part is how much this device helps to take the strain off your body. At 40 years of age, this thing has been a godsend.

[Footerbear]

Footer Dave,

Yeah I footed behind a Sanger and Malibu (inboard) and Flightcraft when went to Ron Scarpa's 2 years ago. I used to own a Flightcraft over here a few years back but it was getting tatty and we sold it when I got divorced.

Im 46 now and know what you mean re the high poles, we've been using them for about 4 years now. I have seen the sites you mention. I tried to get Malibu to build me another Flightcraft the same as Ron's but they werent interested. I must admit the Malibu Barefooter is a great footing boat and the wake is all but perfect the only time you really notice the difference between it and a Flightcraft is if you do a lot of one foot wake crossings, other than that its a great boat, 2 of my mates over here use them.

My boat is basically a Sportique XLR 20 ft, without the integral ski platform, they moulded a flat back on it and beefed up the transom to take the outboard bracket. It has a locker / sundeck at the back instead of the back seat, with two centrally mounted swivelling seats that are the same as the drivers, and then the usual front mounted rear facing wrap round observer seat. It also has airguides, including one in the back for judges, and a skylon pole, plus boom. Will post some pics soon when I find my digital camera, we still havent unpacked all the stuff yet LOL. It's a nice looking boat thats a treat to drive, Morse throttle and hydraulic steering, just needs me to spend a bit more time skiing with it to get the set up spot on. As i said its very close now, so hopefully when I finish the building works at our new home, (one of which is a boat shed with jetty and lift) then I'll get to finish the setting up and get out skiing later this year.

Regards Dave.