250ho set up

[cracker]

Just fitted up a 250ho to by ski boat. its a camero strada 1800... which came out mostly with 150-175hp mercury motors... so for a starter she carrying 50kgs 110lbs more weight in the back then she used too...
any way i took it out for a test run last weekend, ran great lots of power very smooth etc
how ever unless its trimmed in all the way the nose just points to the sky and it porposies out of control.
im guessing a few things here
1 - too much weight in the back...
2 - engine height wrong
3 - too much set back?

there two 1.5" ally spacers between the motor and the jacking plate setting the motor back, im guessing if i removed these my handling/turning would improve?
and it should lessen the leaver effect that trimming the motor out has...?

before this motor it was fitted with a 225hp yamaha
with a 23P 3 blade laser2 it achieved 67mph @ 5500rpm
with the same prop.. it achieved 67mph @ 5500rpm...
whats the go there? just luck? shape of the hull ? the fact that you cant really trim it out at all?
also if you give it w.o.t the boat tends to tip to one side... once again maybe just because its trimmed in so much...

another factor is its still running single cable steering... and has heaps of play in it, seastar pro is on the drawing boards just letting the bank account recover after the full interior re-trim and the new motor...

in any case i was planning on putting the battery in the nose - 25kg up front and maybe the oil bottle another 10kgs up front... i can also move the fuel tank around 300mm more towards the nose to try and help balance the boat better, if that fails some ballast maybe added to the front as well.
also looking at removing some weight from the floor... it weights like 20kg... big old dirty piece of ply wood... its horrid any suggestions for something lighter?

here a picture of the motor height... any suggestions, its just a social ski boat doesnt have to set the world on fire but it would be nicer if it drove abit better then it does now.

suggestions with motor height?

[dnelson964]

Boats are all about balance. You added 110lbs to the transom so you might have to reduce your setback by a good 3" to get rid of the porpoise. I've been there before. Sea star pro would be a good improvement since steering should have 'no' play. If you now have more torque and hp you might be able to turn a higher pitched wheel and that's where you could find added speed potential.

Removing any weight usually helps, replace floor with new 1/2 ply with both sides glassed over (to keep wood dry) would be strong and cheap way. You could have a glass man make a drop in molded liner but that's more money option. Shift weight frontward might help but try to keep weight center line as best you can.

Good luck !

[dzalj1]

Hey mate. I live in brissy. I have the same engine as you and could help you over the phone for your set up. Give me a call when you can. Dennis. 0411343075

[ar300johnson]

I replaced my soft marine plywood floor with Nida Core, a very light composite. It is very light, strong, easy to work with, and will never rot. It is more expensive and I don't know if it is available in Australia. Google Nida Core. The first thing I would do is get rid of the extra setback and add the Sea Star steering. Props also make a big difference in how a boat runs. Also check to make sure that you boat's bottom is straight with no hooks or rockers.

[cracker]

thanks for the information guys, dzalj1 ill give you a bell if i get stuck! thanks for the offer.

i tried running it with a 25P 4 blade trophy on the weekend, no gain in topspeed it was the same again, how ever take off was rubbish, it was a nice smooth prop though to drive i guess you could say, in any case my current one is off getting balanced and cleaned up and im going to raise the motor tonight so that the prop shaft is even with the bottom of the hull and work from there.
the boat turns like a bus atm.
had a bloke who owns a southern 80 6L boat give it a run and see what he thought on sunday said get the motor up heigher and get your prop balanced as it was causing a vibration threw the boat.

[mariawhitetrash]

Lose the setback, that will help loads. Also I think prop shaft level will be too high, that won't help holeshot at all!!

Do you use the jackplate at all or just set it to a height and leave it there?

[GregAdams]

Cracker. I would think about this a bit longer. If you lift your motor that high you will run low on water pressure. That boat was never designed for such a heavy powerhead. In fact it is an inboard hull. They run great with a V8 inside the boat. That boat is one of the rare examples of an Australian inboard manufacturer putting an outboard well on an inboard, that works reasonably well as a recreational outboard. Going that high on a 67 mph boat will ruin what could be a good recreational boat. And no matter what you do to it, it will never be a great high performance boat. If you lift the motor that high be careful cornering. You might get wet! Does your 6 litre inboard friend have outboard racing experience? Sorry for the hard criticism but your boat would make a really nice ski rig, if it were set up correctly.

[cracker]

Lose the setback, that will help loads. Also I think prop shaft level will be too high, that won't help holeshot at all!!

Do you use the jackplate at all or just set it to a height and leave it there?

the holeshot with the 23p laser is great

its got a manual jack plate but iv never touched it untill now

[cracker]

Cracker. I would think about this a bit longer. If you lift your motor that high you will run low on water pressure. That boat was never designed for such a heavy powerhead. In fact it is an inboard hull. They run great with a V8 inside the boat. That boat is one of the rare examples of an Australian inboard manufacturer putting an outboard well on an inboard, that works reasonably well as a recreational outboard. Going that high on a 67 mph boat will ruin what could be a good recreational boat. And no matter what you do to it, it will never be a great high performance boat. If you lift the motor that high be careful cornering. You might get wet! Does your 6 litre inboard friend have outboard racing experience? Sorry for the hard criticism but your boat would make a really nice ski rig, if it were set up correctly.

i understand its not a bullet or a labsport or anything like that, and to be honest its what you said a nice ski rig.
ill see how it goes this weekend if its too high ill drop it down on the jack plate, easy done! just thought there would be something more to be had from this set up other then just whacking it on and hoping for the best. i know with jetski's it takes lots of small adjusments to get it just right and too a point where theres a good trade off with having abit of fun without getting too serious
yeah the guy who who test drove it owns hollowpoint its a stock 6L southern 80 boat.

havent got any more information about strada 1800's? they seem to be few and far between... havent seen any others, other then the one my mate owns( they look great in the water together even the same year, just different colour schemes).



thanks for the input i appreicate it!

[mariawhitetrash]

Your revs are too low with the 23p laser so a 25 Trophy isn't the way to go. Ditch the jack and get the motor bolted straight to the transom and use the holes on the mounting bracket to fine tune your height, I'd guess 2.5" below on the middle hole but that really is a rough guess. No point going too high as you'll overheat and every day drivability will suffer

[cracker]

Lose the setback, that will help loads. Also I think prop shaft level will be too high, that won't help holeshot at all!!

Do you use the jackplate at all or just set it to a height and leave it there?

the set back will be gone once the new steering goes in, atm its required for the cable

[cracker]

Your revs are too low with the 23p laser so a 25 Trophy isn't the way to go. Ditch the jack and get the motor bolted straight to the transom and use the holes on the mounting bracket to fine tune your height, I'd guess 2.5" below on the middle hole but that really is a rough guess. No point going too high as you'll overheat and every day drivability will suffer

pretty sure our rpm would be fine, the old yamaha used to turn 5500 rpm with the same prop... and our etech sees that now easy, so did the trophy... what effect does having it to high have on driveabilty? i thought it would help reduce the porpoising action? time will tell i guess?

[mariawhitetrash]

Your E-TEC needs to see around 5900 at full throttle with a normal load on board. Any less and the motor is working too hard. A 4 blader takes more power to spin in broad terms. Too high will cause a lack of water pressure, trouble getting on plane and slip when cornering. Small changes make big differences!

[cracker]

righto bit of an update i had a few emails come threw saying there was replies here but i cant see them???

any way got some decent steering in her now! seastar with pro helm and lines.
the difference is amazing, it turns really well, very happy with it, brought it from boatstoreusa, very cheap and postage was spot on

i raised the motor 18mm on the jacking plate combined with the new steering the boat drives much better.
did a best of 70.4mph with 4 people full tank of fuel skis, bimini cover up the lot. @5900 rpm this was use a 21P laser though.
also now if you trim the motor to a silly height it will throw a rooster tail 8m or so high which is bloody funny as, taught the mr smart ass jetskier a good lesson on sunday when he was sitting up my ass.

by yourself the without anyone else or gear or rubbish the boat is pretty scary and tends to sit up on the left hand chine and bounces all over the places gets abit hairy at times...

next move will be drop the motor down 5mm see how that fairs and remove the setback blocks and add some weight to the front how ever everything is heading in right direction!

[phantomuk]

you are running way too deep, raise your motor and the nose will come down.