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28-08-2012, 09:21
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#31
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Registered User
Join Date: Feb 2012
Location: NYC
Boat: Hunter E33
Posts: 194
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Quote:
Originally Posted by skipmac
My best suggestion, if you can rev the engine in neutral and see +/- 3600 rpm on the tach but cannot get over 2600 in gear then I would think the tach would be OK. An engine expert might offer some comments here.
Have you inspected the prop or when was the last time you hauled and cleaned? Can you snorkel down to take a look to confirm the prop has no fouling at all?
Also, do you feel any vibration coming from the drive train when motoring at full throttle?
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I'll check and see about doing this in neutral. There hasn't been any noticeable difference in vibration. Also it is new, it's only been in the water a few months so haven't inspected anything since commissioning.
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28-08-2012, 11:46
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#32
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Senior Cruiser
Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 16,306
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Re: Largest Auxiliary Engine Possible
Quote:
Originally Posted by GreggL
I'll check and see about doing this in neutral. There hasn't been any noticeable difference in vibration. Also it is new, it's only been in the water a few months so haven't inspected anything since commissioning.
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A few months would be plenty of time for critters to start growing on the prop. What is the situation where you dock the boat? Some areas have really high growth of barnacles and other organisms that foul your bottom. Maybe ask your dock neighbors.
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
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28-08-2012, 12:04
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#33
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Registered User
Join Date: Aug 2010
Location: sydney, australia
Boat: 38 roberts ketch
Posts: 1,309
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Re: Largest Auxiliary Engine Possible
saw something a while ago about a 2qm20 engine that had been driving an oil pump continuously for 15 years - i apply the same criteria to my boat engine that i apply to any engine - initially find and fix any problems then find the sweet spots and let them do their thing, compare your boat engine to the way you run a car - it has a pretty easy life. i agree that overpropping an engine is not good but diesel engines can take a lot of stress without any detriment. If you eliminate all the other things that could be a cause and end up witj overpropping being the only problem you are probably ok. might be something to take a look at when there is nothing else to fix on the boat (never got to that point meself)
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28-08-2012, 12:20
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#34
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Registered User
Join Date: May 2009
Location: Punta De Mita
Boat: Vagabond 39 Hull # 1
Posts: 1,842
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Re: Largest Auxiliary Engine Possible
On my boat, theoretical hull speed (7.9) can be reached with 75hp. If I doubled the hp I could reach 8.2 knots. Double it again and I can get almost 8.5.
In reality I can get 7 with 51hp.
As far as long diesel life, a friend of a friend has an Isuzu running a refrigerator with 60,000 hours on it. He's changed the oil and one alternator. That's 9.8 years continuous.
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28-08-2012, 12:34
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#35
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Registered User
Join Date: Feb 2012
Location: NYC
Boat: Hunter E33
Posts: 194
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Quote:
Originally Posted by charliehows
saw something a while ago about a 2qm20 engine that had been driving an oil pump continuously for 15 years - i apply the same criteria to my boat engine that i apply to any engine - initially find and fix any problems then find the sweet spots and let them do their thing, compare your boat engine to the way you run a car - it has a pretty easy life. i agree that overpropping an engine is not good but diesel engines can take a lot of stress without any detriment. If you eliminate all the other things that could be a cause and end up witj overpropping being the only problem you are probably ok. might be something to take a look at when there is nothing else to fix on the boat (never got to that point meself)
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I would agree but this engine has had some major issues since delivery
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28-08-2012, 12:42
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#36
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CF Adviser
Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
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Re: Largest Auxiliary Engine Possible
Quote:
Originally Posted by GreggL
I would agree but this engine has had some major issues since delivery
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I'm not convinced you have an engine problem. Sounds more like a prop problem to me.
__________________
cruising is entirely about showing up--in boat shoes.
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28-08-2012, 12:44
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#37
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Registered User
Join Date: Aug 2010
Location: sydney, australia
Boat: 38 roberts ketch
Posts: 1,309
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Re: Largest Auxiliary Engine Possible
[QUOTE=GreggL;1023795]I would agree but this engine has had some major issues since delivery[/QUOTE
looked at yr posts gregg, only thing you've mentioned is the rpm issue and a 50 hr service (???), what other issues has it had?
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28-08-2012, 12:50
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#38
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Registered User
Join Date: Feb 2012
Location: NYC
Boat: Hunter E33
Posts: 194
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Major oil leaks
Starter solenoids burnt twice
Control panels going haywire
And now this stuff.
Only a few months into use.
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28-08-2012, 13:01
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#39
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Registered User
Join Date: Aug 2010
Location: sydney, australia
Boat: 38 roberts ketch
Posts: 1,309
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Re: Largest Auxiliary Engine Possible
is it a new engine or the whole boat is new?
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28-08-2012, 13:31
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#40
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Registered User
Join Date: Feb 2012
Location: NYC
Boat: Hunter E33
Posts: 194
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Quote:
Originally Posted by charliehows
is it a new engine or the whole boat is new?
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Whole boat is new.
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28-08-2012, 13:44
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#41
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Senior Cruiser
Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 16,306
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Re: Largest Auxiliary Engine Possible
Quote:
Originally Posted by GreggL
Whole boat is new.
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Well it is not unusual to have a prop mismatch even with a brand new boat. The basics are science but the fine tuning of getting the exact prop is more an art. When manufacturers change boat design, engine or transmission manufacturers come up with a new model, etc the whole equation is changed.
My ski boat came a bit over propped brand new from the factory and it was not a new model boat or new model engine. Switched to a prop with slightly less pitch and picked up about 700 rpm, 8-9 mph on the top end and out of the hole faster.
But don't loose a lot of sleep over this. Like I said, your engine is not going to explode in the near future but I would definitely put this on the list of things to figure out.
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
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28-08-2012, 13:49
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#42
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Registered User
Join Date: Aug 2010
Location: sydney, australia
Boat: 38 roberts ketch
Posts: 1,309
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Re: Largest Auxiliary Engine Possible
is the warranty support good?
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28-08-2012, 14:38
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#43
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Registered User
Join Date: Feb 2012
Location: NYC
Boat: Hunter E33
Posts: 194
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Quote:
Originally Posted by charliehows
is the warranty support good?
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Honestly, the overall warranty support on the boat is seriously lacking. The engine manufacturer is doing the repairs diligently but new issues keep coming up a there are a lot of manufacturers involved in these multi layered problems.
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28-08-2012, 14:43
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#44
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Registered User
Join Date: Feb 2012
Location: NYC
Boat: Hunter E33
Posts: 194
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Quote:
Originally Posted by skipmac
Well it is not unusual to have a prop mismatch even with a brand new boat. The basics are science but the fine tuning of getting the exact prop is more an art. When manufacturers change boat design, engine or transmission manufacturers come up with a new model, etc the whole equation is changed.
My ski boat came a bit over propped brand new from the factory and it was not a new model boat or new model engine. Switched to a prop with slightly less pitch and picked up about 700 rpm, 8-9 mph on the top end and out of the hole faster.
But don't loose a lot of sleep over this. Like I said, your engine is not going to explode in the near future but I would definitely put this on the list of things to figure out.
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This makes sense. Only problem with this theory may be that I did not have this problem from day one. Is seems to have only begun after my 50 hour service. Certainly haven't changed any hardware since then.
I'm going to check the hull and take it from there.
Thanks everyone for the replies..
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28-08-2012, 18:15
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#45
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Moderator Emeritus
Join Date: May 2007
Location: Ohio
Boat: Now boatless :-(
Posts: 11,580
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Re: Largest Auxiliary Engine Possible
My bet is on bottom and prop fouling...
New boat? I can't believe Hunter put the wrong prop and rigged the throttle incorrectly.
Gregg - I know you have significant powerboat experience. In general sailing boats have "just enough" power and are more sensitive to fouling than powerboats which generally have an excess of power.
Most folks clean/wipe their hulls monthly depending on the sailing area and how much performance they want from their sailboat.
The first check when sailing or power performance/low rpm is suspect are prop wraps and fouling.
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