Martxer
Well-Known Member
Good to know ?
Survey/sea trial
- Thread starter Martxer
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Portofino
Well-Known Member
Assuming it was growth it’s gonna be dog in the season as Prinex had outlined .
Do they do a larger engine option ?
Any way never buy a boat that can’t reach rated rpm .
As for adding options like large Williams Tender , Jet ski , gyro etc etc then the props should have pitch taken out not left overloaded and come the day of sale a quasi excuse banded about at the sea trail .
As said they should reach 3 % or there about over rated WOT rpm .
I mean one explanation could be the motors have been thrashed the EGTs elevated so much so as the PO has tried to reach brochure data speeds = he’s mushroomed the red hot exhaust valves .Thus occurs insidiously ( you don know it’s happening) .
The poor fit and seal of the E valves means it can’t reach rated rpm .
Or burn, t the tips of the turbo ever so slightly as not to show a massive boost reduction but never the less there is one recoded by the engineer on the lower edge of the scale .
As said you need the thing one way or another considering it’s a 2020 boat to reach rated rpm.
Its none negotiable !
Do they do a larger engine option ?
Any way never buy a boat that can’t reach rated rpm .
As for adding options like large Williams Tender , Jet ski , gyro etc etc then the props should have pitch taken out not left overloaded and come the day of sale a quasi excuse banded about at the sea trail .
As said they should reach 3 % or there about over rated WOT rpm .
I mean one explanation could be the motors have been thrashed the EGTs elevated so much so as the PO has tried to reach brochure data speeds = he’s mushroomed the red hot exhaust valves .Thus occurs insidiously ( you don know it’s happening) .
The poor fit and seal of the E valves means it can’t reach rated rpm .
Or burn, t the tips of the turbo ever so slightly as not to show a massive boost reduction but never the less there is one recoded by the engineer on the lower edge of the scale .
As said you need the thing one way or another considering it’s a 2020 boat to reach rated rpm.
Its none negotiable !
rafiki_
Well-Known Member
Porto, why don’t you stick to posting things you know and understand?
When I bought my Azi, she was lifted and cleaned. I noted the props had some damage. We went ahead with the sea trial and she only pulled 26 kn at WOT, down on her stated 32 when new. I made some adjustment for the rib on the bathing platform and the additional kit she was carrying, but requested the owner to repair the props. On the re-trail she pulled 29 knots, which I was happy with. She was happy pulling this speed any time her props were clean.
You know nothing about this boat, how she has been maintained, and what condition she is in, yet you are spouting off. Please stick to facts and I’m sure the current owner will satisfy the OP.
Portofino
Well-Known Member
Then yours is overloaded if it can’t reach rated rpm @ wot .
The extra weight ( quite normal btw ) should mean shave a bit of pitch off
It’s not rocket science . But maybe it in terms of how little folks under stand .See the link I posted ^^^ further up .
No spouting off…
ONCE more .never buy a boat that can’t reach rated Rpm
Its up the owner to present it thus .Wether that means a scrub or in service prop pitch adjustment so be it .
I recall JFM ( who a lot on here still worship) having pitch taken off his props to account for the fins and hard top etc .
No one gives a 8hit of the speed it the rated RPM …….Jesus guys go away and read up .Or listen to Volvo Paul digest what he says .
Portofino
Well-Known Member
The exception to “ never buy a boat that can’t reach rated rpm at wot “ is one thicko owner selling it to another thicko buyer facilitated by a commission hungry broker !
Sorry but I feel that strong about this .
Do your own due diligence of “ over loading “
Sorry mods I don’t want newbies thinking it’s ok not to reach rated rpm at WOT .
Sorry but I feel that strong about this .
Do your own due diligence of “ over loading “
Sorry mods I don’t want newbies thinking it’s ok not to reach rated rpm at WOT .
Pinnacle
Well-Known Member
Nope. The OP has clearly stated that the sea trial took place before the lift and pressure wash. In such circumstances some loss of performance (such as the OP experienced) would be expected.
Portofino
Well-Known Member
This is primeval basic diesel engine boat stuff .Rated rpm @ wot .
If the rest the next level is beyond …drop out .Buts lets in school terms get past CSE / O level before venturing further .
Lost count how many times “ it should reach rated rpm at WOT “
Thats the very best advice.
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rafiki_
Well-Known Member
Porto, I’m not into p!sing contest, so will leave it at this. I’m an Engineer. A proper one, not a technician. Therefore I properly understand most of the technical issues being discussed, so don’t need a lecture on prop pitching and rpm. Are you really suggesting you adjust the prop depending on fuel, water, people load? No, I expect not. The props on my boat worked perfectly thank you. Actually I never felt the need to use WOT in normal use. The OP will find the same. There will be a sweet spot where he and the boat are most comfortable when cruising. All things are a compromise in life, including boating.
I’m 100% confident that the vendor will satisfy the OP, and if he completes, will have a great boat, with the luxury of an extended warranty. Would you offer that?
Portofino
Well-Known Member
Did you miss the two killer Q s i said a prospect should ask irrespective of if you livE 1m or a 1000; miles in my case ..
see post #15 .
Elessar
Well-Known Member
I‘d listen to rafiki. I know his credentials. He doesnt want to brag about it so I won’t do it for him.
I can say he worked for a major automotive brand at the highest level in engineering. A true expert sent to solve problems internationally. He now guest lectures at a major university.
Portofino
Well-Known Member
Which bit of 3 % or there abouts of over rated rpm @ wot do you not understand?= that’s seasonal fouling or weight gain .
The builders + engine supplier s prop them fully loaded .
Over proped or inability to reach rated rpm at wot effects the whole rev range ,Volvo Paul alluded to in his post #31
Blimey .Are you graduate calibre if so which poly ?
Portofino
Well-Known Member
Boat rated diesel over loading is little understood .You are are proving it .Thx guys .
Yeh cars have a gearbox which changes the ratios .It’s a none problem the load , weight , the incline etc .
Elessar
Well-Known Member
Porto you talk crap and there are experts here. I hope the OP can see the difference.
Portofino
Well-Known Member
You have made no usefully contribution to this .Assume it’s over your head .
The op can Google Wot , rpm and overloading to his hearts content .All aligns
Typically .
Prop load vs fuel burn vs overloaded.
Cause of engine overload
Eessar convince me the earths flat ..looks it to the uneducated…….Believe me it’s round and marine motors should reach rated Rpm at wot .
volvopaul
Well-Known Member
The OP either didn’t do his homework or took bad advice from the seller, broker or and engineer. Never carry out a sea trial when buying before lift out and inspection .
Portofino
Well-Known Member
They are not listening Paul.
Away with the boat fairies
Portofino
Well-Known Member
Again no useful contribution.
I think if we were at school together somehow we would be in different sets .Never mind .Hows your wood work skills = better than mine .
lets not loose sight it’s a 202O boat guys .
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volvopaul
Well-Known Member
We could do with knowing the boats model , I remember Scala buying a Bav I think it was a 400 with same motors , I don’t think he’s got it any more because of similar issues relating to short period of hull growth which in turn made the boat unusable without frequent washes . The D4 /6 are constantly monitoring this in turn just backs off the fuel .
Porto I’ve seen too many boats propped empty to reduce speed and rpm as soon as owner takes over , a simple plug in gives the load percentage, it’s all downhill from there .
Sterndrives particularly the DPH prop design soon loose the ability to give what they should through tip damage , growth and hub slippage . Owners really have to keep everything cleaned , this season I have had more calls about loss of speed , black transoms and overheating than any other year this summer weather really has been bad for motor boats in the uk .
Porto I’ve seen too many boats propped empty to reduce speed and rpm as soon as owner takes over , a simple plug in gives the load percentage, it’s all downhill from there .
Sterndrives particularly the DPH prop design soon loose the ability to give what they should through tip damage , growth and hub slippage . Owners really have to keep everything cleaned , this season I have had more calls about loss of speed , black transoms and overheating than any other year this summer weather really has been bad for motor boats in the uk .
Portofino
Well-Known Member
Thing is Paul much to Elessars annoyance i can see load on the dash .77;% gives me 30 knots at approx 1800 rpm and EGT s injection friendly @ 560;* C .
Not saying 77;% is anything to go by .But American sport fisher guys ,professionals run at 80;% load and do 10-15000 hrs between strip downs . Rings , liners, big end s etc .
I will go out to tomorrow and see far off or over 2200 rpm it’s rated Rpm is .Either way .
Lifted in early June .Sat in the Med .
Portofino
Well-Known Member
Straight off the dock just now .
Manufactures rated is 2200 rpm @ 100%load and exactly 140 L / hr .
Normally we cruise at this below
At 20 yrs old I am happy with it . Last lift was early June .
No special treatment before hand or histrionics , excuses .It’s not for sale either !
Manufactures rated is 2200 rpm @ 100%load and exactly 140 L / hr .
Normally we cruise at this below
At 20 yrs old I am happy with it . Last lift was early June .
No special treatment before hand or histrionics , excuses .It’s not for sale either !
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