Problem getting up on the plane

[Mike_S]

Just wondering if more knowledgable forumites can help me here

Out on our Regal 2150 at the weekend with 4 friends (6 people in total, none of whom are particularly big) and found that the boat was *really* struggling to get on the plane, or even to get moving and it's got me slightly concerned. Once it's on the plane it's fine. Normally with just the 2 of us, she's up and running within 10 seconds or so but whenever we've had people on it's been knocking on for a minute and even then it's only gone because the wife's gone into the cuddy to put more weight forward. We've tried having more people in the middle of the boat but that's not really worked either.

Probably 3/4 tank of fuel on at the moment, 5litre V8 so shouldn't struggle power wise I'd have thought ? It's got a s/s "vengeance" 3 blade prop and I've checked the number on it to see if it's correct and it's the same as originally fitted when new I think (says 23R on it iirc). Leg was fully down and it's fairly clean underneath having only been out a few weeks ago.

I'm not so fussed about top end speed, I'm more concerned about it actually getting up and out as we want to use it for wakeboarding next year so it'll always have at least 4 people on and at this rate, it'll not get out of the water to let us /forums/images/graemlins/frown.gif Is it just a trait of the fastrac hull design or is there something I can do to help it ? I've tried building speed slowly but to me that does kind of defeat the object.

Thoughts anyone (apart from lose some weight you fat pieboy) ?

Cheers

Mike

 

[[2068]]

6 people is quite heavily loaded, but it does sound like the engine might be a bit down on power.

Things to check include ignition timing, compression, etc... you didn't say if the engine was a carb or EFI...

dv.

 

[Whitelighter]

Sounds to me like you need a new boat /forums/images/graemlins/laugh.gif

 

[KevB]

I think this is where the difference between diesel and petrol shows. A diesel of similar power would probably get you on the plane much easier because it's torque band is down low. Where as a petrol needs to be whizzing to get up in it's high torque range.

Leg in, tabs down and move weight towards the front.

Years and years ago I used to have a speed boat with an outboard which was slightly under powered for the amount or weight we carried. I fitted a set of hydrofoil fins on the cavitation plate and it deffinitely made a difference and helped with getting the boat planing.

 

[Mike_S]

It's a fuel injected Mercruiser unit, should be 240hp.

With the 2 of us on it flys, certainly seen 50+knots very recently. It's just the loaded scenario that concerns me so I'm wondering if the prop's wrong or if it's something else.

 

[[2068]]

True about the torque curve, but as an example, brothers Rinker 232 with a 5.0EFI Volvo leaps on to the plane with 5/6 people (thin ish, somewhat younger people admittedly), then goes on to 38kts.

dv.

 

[Mike_S]

[ QUOTE ]
Sounds to me like you need a new boat /forums/images/graemlins/laugh.gif

[/ QUOTE ]

/forums/images/graemlins/laugh.gif Now why did I guess you'd come out with that one eh /forums/images/graemlins/tongue.gif

Having just bought a new V8 towcar for this boat, I can't stretch to a new boat as well /forums/images/graemlins/tongue.gif Going to miss SIBS now as well as we'll be out of the country so I'll have to wait to see it for real /forums/images/graemlins/wink.gif

 

[[2068]]

50kts !!!! /forums/images/graemlins/blush.gif

That's one hell of a top speed.

Changing the prop to one with a shorter pitch would drop a few knots off the top speed, but would help getting on the plane. Someone who actually owns one of these boats could give you a better idea of exactly which one to go for.

dv.

 

[BrokerBen]

It sounds like your instruments might be a little optomistic...

Anyways, 240hp isn't in the grand scheme of things that much, and the hull although a planing hull has been built largely with price in mind so will struggle when laden.

Perhaps see what stores you have on board and move them around. Either way, out on the solent almost every boat goes past making a huge wash and with the bow pointing to the sky, but I seem to remember a planing boat should be on the surface of the water, no making much wash and should be level trimmed almost...

Perhaps talk to somebody about tuning some more ponies from the engine? 240hp isn't many for a big V8, imagine if you only got 240hp out of a V8 in your car... And cars dont have a constant supply of nice cold cooling water to play with!

 

[Nick_H]

How clean is "fairly clean"? Its amazing what effect even a thin layer of slime on the hull or a few barnacles on the prop can have, and on a heavily laden boat could stop you planing. Is it left in the water? Is it anti-fouled?

 

[Mike_S]

Can GPS be optimistic ? I know where you're coming from though.

Once on the plane and trimmed, it sits pretty level and there's a noticeable difference in pitch, noise and speed when trimmed out properly.

As for tuning the engine, having spent countless thousands doing that to cars over the years I doubt the financial controller will allow it with the boat. A prop change can be done in exchange for another pair of shoes though no doubt /forums/images/graemlins/wink.gif

I'll try moving stuff about but to be fair, most of it's in the middle / forward anyway.

 

[Kawasaki]

[ QUOTE ]


Thoughts anyone (apart from lose some weight you fat pieboy) ?

Cheers

Mike

[/ QUOTE ]

Sounds like You've answered Your own Question /forums/images/graemlins/wink.gif

Puzzling innit?
Apart from banishing SWMBO to the cuddy let's think about it.
1 , check there is no water in the hull.
2, Is the bottom Super Clean or just cleanish?
3, Has the boat, since in Your ownership ever got on the Plane with a bunch of folks on?
Sounds like all the other angles have been checked by Yourself.

Duoprops?
Don't really know what I am talking about there, don't even know if that set up is poss on Your boat.
Thinking out loud that's all!"

Apart from 1 or 2 all I can think of is weight duistribution.

The cleanleness of the bottom makes a heck of a difference IMHO

 

[Mike_S]

[ QUOTE ]
How clean is "fairly clean"? Its amazing what effect even a thin layer of slime on the hull or a few barnacles on the prop can have, and on a heavily laden boat could stop you planing. Is it left in the water? Is it anti-fouled?

[/ QUOTE ]

Yes, left in the water and antifouled. It's in Cardiff Bay, so freshwater. As for growth I noticed some slime on the leg but after a run out in the bristol channel that cleared off. There's a lovely green stain round the waterline but nothing really visible below it on the antifoul. The prop was green as well, but again, after a run it was pretty clean (but by no means shiny all over)

 

[ValleyForge]

10 secs to get on the plane is a long time - & rubbish for skiing / wakeboarding - Try (borrow) a finer pitch prop, say 19''.

 

[Overdraught]

We have a Sea Ray 260 sundancer, a 4 berth cruiser, with a 5.0 efi and a Bravo 2 single prop leg. We regularly have 4 x adults and 4 x children, plus dinghy, outboard, never less than 3/4 fuel, water etc. We plane without a problem, leaving the trim tabs alone.

I've had 8 blokes and luggage on board and that required some moving forward and 30 seconds or so.

Your boat should be lighter so better power:weight.

Although ours is dry stacked, she's antifouled but clean.

Sounds like your prop may wrong if you're getting 50 knots

 

[gjgm]

is it still ok with just the two of you? But if you really hit 50knts (is that GPS or speedo?), I think the prop has been selected for top end, at the compromise of low down grunt.
Shouldnt take 60 seconds to get on the plane even with 6 people...how long have you had the boat?

 

[duncan]

mike - just get a 'fully loaded and water ski prop' plus that pair of shoes.

did you happen to notice what revs the engine was pulling at wot when fully loaded and how this compared with your normal 2 up running? personally I would get a second prop at 4" pitch lower for skiing based on what you have said here - you could invest in a 5 blade but that would probably also involve a trip to Jimmy Chou (although they have an online sale on currently.......)

 

[Mike_S]

Kawasaki, full spec is she's a 240hp V8 Mercruiser EFI, with Bravo 1 leg, so single prop. Only thing different from stock as I can tell is the s/s prop, but with my limited knowledge I'd have thought that would help, not hinder.

Of your ideas, 3 is interesting as I don't recall it ever being any good with more than 4 people on (it's plated as being OK for 6), but with 4 on it doesn't struggle at all really. I might whip her out one weekend for a scrub then pile some friends on to see if there's a difference.

 

[Mike_S]

[ QUOTE ]
is it still ok with just the two of you? But if you really hit 50knts (is that GPS or speedo?), I think the prop has been selected for top end, at the compromise of low down grunt.
Shouldnt take 60 seconds to get on the plane even with 6 people...how long have you had the boat?

[/ QUOTE ]

GPS and yes, with 2 of us on she's absolutely fine in my albeit limited experience. It's up and out on the plane in seconds, I'm certainly throttling back and trimming the leg within 10 seconds I'd guess. Only had the boat since April and this is our first foray into boat ownership, all my previous experience was 20 years ago as a kid with 14' Fletchers so I don't really remember that !

WOT is somewhere in the region of 4700rpm I think, but to be honest I haven't run it flat out as ~4500 was giving it 50kts anyway. That's with 2 of us on though, with more than that I don't go anywhere near flat out but from memory I don't think it wanted to go over 4k rpm anyway but I may be wrong, I'm more interested in a smooth ride when I've got friends on board so tend to cruise at ~3krpm.

Interesting though in that others with the same engine size and heavier boats aren't struggling (albeit with different hull designs and legs).

 

[emcm0025]

Having just had speed and planeing issues due to the prop and after trying 3 different types I think i've got it right my engine is the older 5L 220hp. I would suggest you have a look at the propeller calculator on the mercury site just to see where your current prop shows
link
http://sites.mercurymarine.com/portal/page?_pageid=126,48417&_dad=portal&_schema=PORTAL

hope the link works