[Emrys]

Hi all, have been reading a lot of your threads but this is the first time I've written one, knew I'd have to start someday.
Just had delivery of a new barracuda7 ( Isn't that what pensions are for!) and am 90 % pleased. The not so pleasing 10% is the handling of the boat. When turning either to port or especially to starboard at planing speed the prop ventilates, is this normal? I'm used to Warrior boats which don't have this problem. The engine is a suzuki 150 and is at the correct height on the transom. I have two transducers fitted about 1ft each side of the center line of the boat. Could they be causing this? Any comments regarding this will be very much appriciated.

 

[Norm B]

Hi all, have been reading a lot of your threads but this is the first time I've written one, knew I'd have to start someday.
Just had delivery of a new barracuda7 ( Isn't that what pensions are for!) and am 90 % pleased. The not so pleasing 10% is the handling of the boat. When turning either to port or especially to starboard at planing speed the prop ventilates, is this normal? I'm used to Warrior boats which don't have this problem. The engine is a suzuki 150 and is at the correct height on the transom. I have two transducers fitted about 1ft each side of the center line of the boat. Could they be causing this? Any comments regarding this will be very much appriciated.

Do you mean the prop cavitates? If it does it's because it's too shallow or too much pitch.

 

[Clinker]

Shouldn't be normal - I have a 21ft boat with a 150 - mounted quite high - previous owner had it raised as it had been mounted a bit too low which is common with a lot of manufacturer mounted outboards - if I'm trimmed right out I can induce a bit of ventilation when turning hard at speed, but with the engine normally trimmed it just tracks round the corner really nicely. I have an Enertia prop which is specifically designed to have a lot of grip though.

As the boat is new, I would refer it back to the dealer - if you're running correctly trimmed, to me that's not acceptable on a boat with that reputation, not to mention cost! Can you tilt the transducers out of the water so they can be eliminated as a cause? Perhaps a change of prop is in order?

Aside from that, I hope you're enjoying the new boat - can we see some photos?

 

[Emrys]

Thanks NormB and Clinker, the cavitation plate is level with the bottom of the boat so the height should be right, when it gets its first service I will remove the transducers and see if it makes a difference, if not then I'm stumped.

 

[garry23flyer]

lovely looking boat.

have you got a better pic of the back of the boat with the engine.

id say engine height and prop is most likely cause.

i dont think the transducers would effect it that much. maybe a little but not as much as you think they may be effecting it.

most boats can easily handle having the engine lifted up a few holes.

next time out have some one look over the transom when up on the plane and going pretty fast and see if you can see the cavitation plate?

if you cant see it then the engine is too low.

the standard suzuki prop just might not be the right design for your hull.

ive got twin 115 mercs on my boat and the standard props were useless.

my engines are on a pod which raises the engines up nearly 4" over where they would be if mounted directly to the transom.

ive now got 4 bladed props fitted which transformed the boat completely.

 

[Emrys]

Thanks NormB and Clinker, the cavitation plate is level with the bottom of the boat so the height should be right, when it gets its first service I will remove the transducers and see if it makes a difference, if not then I'm stumped.

lovely looking boat.

have you got a better pic of the back of the boat with the engine.

id say engine height and prop is most likely cause.

i dont think the transducers would effect it that much. maybe a little but not as much as you think they may be effecting it.

most boats can easily handle having the engine lifted up a few holes.

next time out have some one look over the transom when up on the plane and going pretty fast and see if you can see the cavitation plate?

if you cant see it then the engine is too low.

the standard suzuki prop just might not be the right design for your hull.

ive got twin 115 mercs on my boat and the standard props were useless.

my engines are on a pod which raises the engines up nearly 4" over where they would be if mounted directly to the transom.

ive now got 4 bladed props fitted which transformed the boat completely.

thanks for the advice garry, I'll certainly look into the height/prop suggestion. There is a high 'wash' behind the boat when off plane is this normal in a 24' 2t boat? Any other Barracuda owners out there?

 

[garry23flyer]

just because cavitation plate is level with the bottom of the hull dosen't mean that it is correct height.

thats just the standard height for most longshaft or extra longshaft engines.

its a starting point which you dont want to go any lower otherwise you'll cause lots of drag.

whoever fitted the engine probably dont really get in too engine height adjusting much as it can mean a lot of unbolting and bolting etc until you get the best position.

not all longshaft engines are the same from cavitation plate to top of transom.

your suzuki could be say 20" and my mercs could be 20 1/2" or 19 1/2".

they all differ in height slightly.

 

[Andydavy]

almost certainly incorrect prop pitch. refer it back to dealer and they should swap prop. what are your revs at wide open throttle?

 

[Emrys]

Thanks for the information everyone, the engine has just done 10hours, so I'll be able to go to wot next time out, I'll see then if a wrong pitch prop is the reason for the ventilation, it does seem to rev up quickly

 

[garry23flyer]

prop could also be slipping.

mine when it had the merc props on slipped like mad.

now got 4 bladed props on which grip all the way through the rev range.

when you know what max rpm your getting post up the prop size as well so i can check the prop slip calculator.

will also need to know speed at max rpm.

 

[nab raider]

I recently sold a Barracuda 7 which had a 175 Suzuki. I never had any cavitation problem unless I trimmed it well up. I think the warrior you had was a sportier boat than the Barracuda mine was always slow off the mark but fine when you got up to speed. I had a through hull transducer which might be what you will have to do.

 

[Emrys]

Thanks for all the comments, when I find out the max rpm e. t. c. I will post it and hopefully get some more suggestions.

 

[Emrys]

Hi all, went out on Sunday 4x13st fellas, plus fishing gear and 100lt fuel. W.o.t. At 5750 reaching 28 knt Covered 26mls and used 32lt of fuel..prop still ventilating(cavitating) when turning port or starboard at 15+ knt. See U Tube under IDISHIDO, (I'm the old guy ) wish we could have put the camera under water when planing to see what was happening. The cavitation plate was in sight when planing and Beneteau say the 151/4 x 19 is the correct prop, they are still looking into the problem. Thanks for any comments.

 

[nab raider]

The speed RPM and fuel consumption are spot on so not sure what is causing cavitation. As I said mine did not do it. Are we talking about severe turns causing it?

 

[nab raider]

The speed RPM and fuel consumption are spot on so not sure what is causing cavitation. As I said mine did not do it. Are we talking about severe turns causing it?

Have

The speed RPM and fuel consumption are spot on so not sure what is causing cavitation. As I said mine did not do it. Are we talking about severe turns causing it?

Have sent you a PM.

 

[Clinker]

Hi all, went out on Sunday 4x13st fellas, plus fishing gear and 100lt fuel. W.o.t. At 5750 reaching 28 knt Covered 26mls and used 32lt of fuel..prop still ventilating(cavitating) when turning port or starboard at 15+ knt. See U Tube under IDISHIDO, (I'm the old guy ) wish we could have put the camera under water when planing to see what was happening. The cavitation plate was in sight when planing and Beneteau say the 151/4 x 19 is the correct prop, they are still looking into the problem. Thanks for any comments.

Using less than 8gph with a 150 at 5750 rpm (unless I've misunderstood what you're saying) - if you haven't made an error that is staggeringly good.

 

[Emrys]

Hi nab raider, been watching the football Will tel. You tomorrow night, turns were not tight. At one point the boat came to a stop But re engaged when put into neutral and then forward. Thanks for your reply Clinker, we were out for two hours with engine running all the time. Will tilt up the transducers next and if that does not work I will be tempted to use a 4 bladed prop.

 

[headlight]

Hi all, went out on Sunday 4x13st fellas, plus fishing gear and 100lt fuel. W.o.t. At 5750 reaching 28 knt Covered 26mls and used 32lt of fuel..prop still ventilating(cavitating) when turning port or starboard at 15+ knt. See U Tube under IDISHIDO, (I'm the old guy ) wish we could have put the camera under water when planing to see what was happening. The cavitation plate was in sight when planing and Beneteau say the 151/4 x 19 is the correct prop, they are still looking into the problem. Thanks for any comments.

I am guessing that that wasn"t 26 miles covered at WOT as that would have been well over 100 litres used & not 32 litres.
32 litres would suggest that the majority of the 26 miles was covered at a nice economical cruise & the "5750 at WOT reaching 28kts" was just a short burst to see what she would do ?
Very good consumption figures non the less.

 

[Emrys]

That's right headlight, fuel consumption is ok I'ts just the ventilating when turning that's a concern, thanks for you'r interest.

 

[headlight]

How far out was the engine trimmed when this happened ?