Am I Throwing Good Money After Bad??? Please Help...

[roykinch]

Can someone help me with this problem please?

I have a Sunseeker Portofino 375 with twin Kad 42's. This is a very heavy boat and being coded (extra safety equipment/weight) and a life raft for 10 (8+2) and most of the seating directly above the engines.

I have had many problems with these engines because in my opinion this boat is very underpowered, or am i missing something ie are the props wrong? about 2 seasons ago i put on some stainless steel C4 props as I had alloy B5's on before. This helped getting on the plane a lot, but now she seems to take longer and longer to get up. There is also a huge load on the engines that forces small oil leaks and small water leaks here and there.

I went to the boat show last week to look into re-engining but this will not be cost affective.

Talking to Paul at Costal Rides today who was very helpful, he recommends going back to Alloy and instead of going back to B5's to go for B4's which will lead to getting on to the plane quicker and reduce the load on the engines in return for less top end speed (which will hurt me - I cant pretend it won't).

I think I will also get her scrubbed more often because this also makes a big difference to the performance.

AM I JUST THROWING GOOD MONEY AFTER BAD? I just can't work this one out.

Should I just get a newer bigger engined, more modern Sunseeker?

It has to be a Sunseeker because of my business name and website - plus I love them so very much even after all the grieve she has given me in the engine room.

Someone please help.....

Roy

 

[sarabande]

I don't wish to be unsympathetic towards someone with a boat problem, but you are doing this in order to run a charter company which emphasises speed, thrills, and luxury.

If you have all these engine oil and water leaks, and prop problems, you need to consider whether a new boat might not answer these issues better, rather than risking loss of reputation and revenue through breakdowns or accidents.

 

[Deleted User YDKXO]

Maybe the Portofino 375 looks a bit underpowered with KAD42's now but at the time that the boat was built (late '90's??), she would not have been considered underpowered. There were larger boats around at the time such as the Princess V40 fitted with the same engines. I dont think anyone can advise you whether its worth trading up or not because you dont say whether this issue is affecting your charter income and how much money you're spending on keeping the engines going. My inclination would be to try to sort out your existing boat because in all likelihood, the cost of selling your existing boat in terms of taking the depreciation hit and brokers fees, will be more than the cost of optimising your props/engines. I dont think its worth fiddling about with props to try to improve speed onto the plane. The right thing to do is to size the props to achieve max engine rpm + 100-200rpm and then, if the boat still doesn't perform, its probably an engine issue. The KAD42 is sensitive to valve clearances. Have you had this checked? Have you had the injectors and fuel pump serviced?
If, once you're sure that the engines are giving 100% and the props are correctly sized, the boat still fails to perform adequately for your charter operation, then is the time to consider selling. All IMHO

 

[Sundowner Portofino]

We have the Portofino 32 with KAD 42's and these are big enough for the boat, but any bigger and I think we would be underpowered.

We get up easy and can hit flat out speeds of about 44 knots.

Having said that we very rarely (and I mean very) use even 2/3 of this speed and tend to spend most of our time at around 25 - 30 knots.

IMHO people we have taken on the boat who have little experience of MOBO's get more thrills when we bank sharply into a corner or buzz past the Needles in really close. The high speed stuff, unless on glass water just gives everyone back ache.

So for me I would swap the props to get you on the plane quick and lose the top end. Less strain on the engine.

Or if speed is of serious importance swap her for a Super Hawk as I am reliably told they are excellent for charter work.

Best of luck

 

[Sundowner Portofino]

PS how many hours have the engines done? And have they had their big service when they get taken out of the boat?

We did this 2 years ago and the difference was noticable, probably put 10% on the top end 40 to 44 knots and she seems to kick up onto the plane a bit quicker.

Not cheap mind you

 

[duncan]

the bit I don't understand is how the boat was performing so well back in April - and is is suddenly 'underpowered'?

generally I would start with a thorough clean, outside for drag/efficiency and inside for weight (it's at this time of year you find 400kg of gear has somehow accumulated in the lockers) - this gives you back your baseline and you should log revs v speed.

now add 800kg somehow - to simulate passengers (obviously passengers would be the easy way) and repeat the log readings

comparing the 2 sets gives you the information to realistically assess likely prop change/performances

finally - do you have boost guages on the engines? this is obviously another area to be checked off.

 

[roykinch]

Thank you all for your input, you have helped me think a little straighter, i will be taking a little (if not all) of your very helpful advise. First of all i'm going to go through all the lockers as i think even i could do this, i will ask if i could have a storage box on the pontoon and put all the cleaning products etc into it. I will now try and run at half tanks of fuel and reduce the amount of water in the holding tank.

Answers to questions:
890 hours each (full rebuild to Port side last winter (now 108 hours since) + stripped down Starboard side and skimmed head, acid cleaned cooling parts etc.

3500 revs

No boost gauges

Top speed 32 knts

Valve clearances checked, injectors all overhauled, diesel pumps all reset and tested.


Below is my plans so far -

Weight stripping programme:

Go out as she is & log revs, time to plane, top speed, loadings on engines.
Engine temps.
6+2 crew

Then:
Go through all lockers and strip out all weight.
Run at max half fuel (maybe put on new fuel gauge).
Re-prop - speak to steel developments & mike (lifeboat) & Paul at Coastal Rides.
Reset fuel pumps.
Lift & clean bottom of boat.
Keep water & fuel levels low (work out weight of fuel)

Any other thoughts?

Best regards and thanks again

Roy

 

[Col]

Go through all lockers and strip out all weight.
Run at max half fuel (maybe put on new fuel gauge).
Re-prop - speak to steel developments & mike (lifeboat) & Paul at Coastal Rides.
Reset fuel pumps.
Lift & clean bottom of boat.
Keep water & fuel levels low (work out weight of fuel)

I think you have these in the wrong order.
Scrub the bottom before you touch the pumps, props or anything mechanical. Then start with the basics- a service and check tappets, if still off the mark- get the injectors tested. This is all easy stuff and in the great scheme of things -the cheaper option. Your looking at up to£1000 each to overhaul pumps plus the removal/ refit costs as the timing will need checking afterwards.

 

[PaulGooch]

Fuel tanks need to be kept as full as possible at all times.

 

[PowerYachtBlog]

IMO you need a reprop as your friend told you. 3500 rpm is like from 300 to 500 revs less on the 42s 230hp engines. Can you lend some B4 to try them out.
What revs you used to make with the B5 versus the C4s.
32 knots is not bad, for that boat but I think new they where capable of like 35 knots which still might be possible if you have the good props. That is what more or less a 37 Targa does which weighs like a quater ton less but is wider and a has a deeper hull in the fore sections.

As someone said check the following:
- fuel lines, tanks and filters and is also another bonus.
- antifouling, may be she needs a strip down as old antifouling has build up.
- for how many weeks or months does the boat stay on land. Sometimes the first layer of gelcoat absorbs the water and then can add like to half a ton of weight in the long term. On the old polyester boats I have seen 40 footers add a ton to it!

I checked some brokerage listings and everyone advises speeds of 32 to 35 knots on the 375 with the same engines.
As for the planning do you keep the stern drives all down, and tabs closed in? Sunseeker because they have a more deep vee aft like 20 degrees deadrise do usually need a knot or two more speed to plane (surely 18+) so it is important that you have the stern drives all closed up. This is normal routine on all stern drive boats because like this you always stress the drives and bellows less.

 

[jfm]

Sometimes the first layer of gelcoat absorbs the water and then can add like to half a ton of weight in the long term. On the old polyester boats I have seen 40 footers add a ton to it!

That is just absolute total garbage. A 40footer has underwater surface area of about 11m x 4m. A slab of water measuring 11m x 4m has to be ~23mm thick to weigh a tonne. There is no way a grp hull absorbs more water than its own thickness/volume.

 

[rlw]

Roy,

I am looking at a similar thing for my T40. I think coastal rides is right.
From what I have learned from reading the web. A C4 stainless prop is approx the same pitch as a B5 Alloy one. The C4 will give you a better top end because it does not flex as much but won't solve the loading issue. I let the experts comment on this but if you are getting 3500 revs now and you drop to B4's you shoud gain around 200 rpm which I guess will compensate most of the speed loss.

I have a targa 40 since early this year. It has C5's but struggles to get past 3500 revs whhen loaden for cruising. I plan to drop a size for next seazon hoping to get the boat back to WOT.
She now does 29 knots with C5's but originally was shipped with C4's and a brochure speed of 31-32 knots. She does have a genny and aircon so is pretty heavy I guess.

The volvo prop sizing tool is available on the volvo we site. gives you a good indication of the impact of prop changes. The top speeds/rpm are a bit optimistic.

Rob

 

[PowerYachtBlog]

That is just absolute total garbage. A 40footer has underwater surface area of about 11m x 4m. A slab of water measuring 11m x 4m has to be ~23mm thick to weigh a tonne. There is no way a grp hull absorbs more water than its own thickness/volume.

Yeah right I just thrown a figure there without doing mathematics. But I do remember a few years ago it was close to a ton on a 55 footer, which stayed 2 years plus in the water. I was actually impressed myself about this, and the owner stated the difference after the boat dryed up which took about a month and launched it with new paint that was a ton less in weight.

 

[jfm]

I do remember a few years ago it was close to a ton on a 55 footer, which stayed 2 years plus in the water.

By the same maths, it will never ever be close to a tonne even on a 55 footer. 25kg more typical. Do the maths and the chemistry - it isn't difficult

Sure, an owner might have said a ton. But he must be wildly wrong. No 55 footer can absorb a tonne of water into the GRP. It would need to be made of Weetabix to hold a tonne of water. People say all sorts of stuff about their boats when in the dock or on the internet. You are a boat expert so don't believe it just cos a boat owner said it!

 

[Sundowner Portofino]

By the same maths, it will never ever be close to a tonne even on a 55 footer. 25kg more typical. Do the maths and the chemistry - it isn't difficult

Sure, an owner might have said a ton. But he must be wildly wrong. No 55 footer can absorb a tonne of water into the GRP. It would need to be made of Weetabix to hold a tonne of water. People say all sorts of stuff about their boats when in the dock or on the internet. You are a boat expert so don't believe it just cos a boat owner said it!

With JFM on this one, I think that said owner was pulling your plonker. Even if that much water could be absorbed (which it can't) it would have taken a good deal longer to evaporate than one month on the hard, maybe a few years ashore.

 

[Wiggo]

It would need to be made of Weetabix to hold a tonne of water.

So a bit like Gludy's old Trader, then?

 

[PowerYachtBlog]

Yes if I do the mathematics is easy. 1 large can of Armor All Wurth antifouling I give 2 coats and thats about 10 kgs alone. That is a bottom of 10 meters plus 3.60 and an average depth of say 1 metre.
Yes this was long ago and it was my technical inexperienced period. But somehow even with a clean hull and gear boats do loose a couple of knots in the end of the season, and I never understand why. So moving forward I still unwillingly attribute that loss of speed to water absortion of the hull.

 

[jfm]

moving forward I still unwillingly attribute that loss of speed to water absortion of the hull.

Feel free! Sure you may attribute it to water absorption if you wish, just as you may believe in Father Christmas

 

[MapisM]

somehow even with a clean hull and gear boats do loose a couple of knots in the end of the season, and I never understand why.

'Cause the crew gets fatter and fatter during the season, that's why!

PS: which 10m hull r u talking about, with an average depth of 1m?!?
A steel tug, or summink?

 

[Col]

IMO you need a reprop as your friend told you. 3500 rpm is like from 300 to 500 revs less on the 42s 230hp engines. Can you lend some B4 to try them out.
What revs you used to make with the B5 versus the C4s.
32 knots is not bad, for that boat but I think new they where capable of like 35 knots which still might be possible if you have the good props. That is what more or less a 37 Targa does which weighs like a quater ton less but is wider and a has a deeper hull in the fore sections.

As someone said check the following:
- fuel lines, tanks and filters and is also another bonus.
- antifouling, may be she needs a strip down as old antifouling has build up.
- for how many weeks or months does the boat stay on land. Sometimes the first layer of gelcoat absorbs the water and then can add like to half a ton of weight in the long term. On the old polyester boats I have seen 40 footers add a ton to it!

I checked some brokerage listings and everyone advises speeds of 32 to 35 knots on the 375 with the same engines.
As for the planning do you keep the stern drives all down, and tabs closed in? Sunseeker because they have a more deep vee aft like 20 degrees deadrise do usually need a knot or two more speed to plane (surely 18+) so it is important that you have the stern drives all closed up. This is normal routine on all stern drive boats because like this you always stress the drives and bellows less.

He says he has lost performance gradually, not as a result of changing props

i put on some stainless steel C4 props as I had alloy B5's on before. This helped getting on the plane a lot, but now she seems to take longer and longer to get up.

Still should check everything else before committing to expense of repropping. You don't try and cure barnacles on the hull with new props and injector pumps!