Brian Posted November 12, 2012 Report Share Posted November 12, 2012 Jamie I'm probably going down to Rockley on Thursday, if I do, I'll pop the manual in. I don't need it so you're welcome. Quote Link to comment Share on other sites More sharing options...
Jamie W Posted November 12, 2012 Author Report Share Posted November 12, 2012 Jamie I'm probably going down to Rockley on Thursday, if I do, I'll pop the manual in. I don't need it so you're welcome. Your a star, thanks Brian. Wouldn't attempt anything major on the engine. But I think it's safer to have a little knowledge.. Quote Link to comment Share on other sites More sharing options...
Rob Posted November 12, 2012 Report Share Posted November 12, 2012 3500 I'm 2-3 knots down also Sorry if i missed this, but how do you know? Or is this from previous performance of your boat? If you are going by manufacturer quoted figures - i would assume that they don't always tell the 100% truth, maybe they had \ you had 2-3knts of tide when took that reading. If it is a manufactures claim, do you have exactly the same prop? Is it in perfect condition and prefectly balanced? Just because it says 19x17 ect doesnt mean it hasn't been tuned and changed by a prop repair company. If the boat wasn't new to you, the previous owner may have wanted a quicker-to-plane time etc etc, or just tweaked the prop on the Training Bank and had to have it made smaller to be balanced. Sort out the coolant issue - as that is a worry. I had a coolant issue with a past car, it would loose water, and i thought the worst as it never leaked any on the drive! Answer was: when up to temp \ full coolant pressure, the seal on the water pump would weep - at rest or cold, no leak! Rob Quote Link to comment Share on other sites More sharing options...
Jamie W Posted November 12, 2012 Author Report Share Posted November 12, 2012 (edited) 3500 I'm 2-3 knots down also Sorry if i missed this, but how do you know? Or is this from previous performance of your boat? If you are going by manufacturer quoted figures - i would assume that they don't always tell the 100% truth, maybe they had \ you had 2-3knts of tide when took that reading. If it is a manufactures claim, do you have exactly the same prop? Is it in perfect condition and prefectly balanced? Just because it says 19x17 ect doesnt mean it hasn't been tuned and changed by a prop repair company. If the boat wasn't new to you, the previous owner may have wanted a quicker-to-plane time etc etc, or just tweaked the prop on the Training Bank and had to have it made smaller to be balanced. Sort out the coolant issue - as that is a worry. I had a coolant issue with a past car, it would loose water, and i thought the worst as it never leaked any on the drive! Answer was: when up to temp \ full coolant pressure, the seal on the water pump would weep - at rest or cold, no leak! Rob http://www.yachtworld.co.uk/core/listing/boatMergedDetails.jsp?boat_id=2306368&checked_boats=2306368&ybw=&units=Meters Edited November 12, 2012 by Jw2000uk Quote Link to comment Share on other sites More sharing options...
Brian Posted November 12, 2012 Report Share Posted November 12, 2012 A bit of slime could easily knock 2 kts off your speed. Quote Link to comment Share on other sites More sharing options...
niggle Posted November 12, 2012 Report Share Posted November 12, 2012 Has yours had a rope cutter fitted?..... If so that's the reason Nige Quote Link to comment Share on other sites More sharing options...
Brian Posted November 12, 2012 Report Share Posted November 12, 2012 A bit of slime could easily knock 2 kts off your speed. About 40 years ago the we were looking at ways of reducing the drag of warships, to gain speed for less fuel. We fitted nozzles at the bow and injected all sorts of "slime" etc. to make the hull more slippery. It didn't work, most resulted in a loss of speed or increased fuel consumption. Quote Link to comment Share on other sites More sharing options...
Rob Posted November 12, 2012 Report Share Posted November 12, 2012 Read this: http://www.pbsbac.co.uk/forums/index.php?showtopic=9269 Adam had a slowing issue with JV - as he said 3500rpm usualy gave 25knts - here it was giving only 10knts - all down to the green stuff! Rob Quote Link to comment Share on other sites More sharing options...
Jamie W Posted November 12, 2012 Author Report Share Posted November 12, 2012 Has yours had a rope cutter fitted?..... If so that's the reason Nige No rope cutter nige.. Will service, and beach to clean slime.. And go from there.. Obviously after sorting coolant.. Will have a read of tht rob ;-) Quote Link to comment Share on other sites More sharing options...
Jamie W Posted November 12, 2012 Author Report Share Posted November 12, 2012 A bit of slime could easily knock 2 kts off your speed. Would slime lower ur RPM range? I know it can affect speed.. But not sure on the rpm :-/ .. Prob a silly question lol.. Quote Link to comment Share on other sites More sharing options...
Brian Posted November 12, 2012 Report Share Posted November 12, 2012 Yes. If you're not getting the speed, you won't get the revs. You won't make the prop slip more. Quote Link to comment Share on other sites More sharing options...
Wedger Posted November 12, 2012 Report Share Posted November 12, 2012 On balance looking at all of this I would look at fouling for the speed prop issue. ........ and as Nige says very important to find out where that coolant is going! Quote Link to comment Share on other sites More sharing options...
great white Posted November 12, 2012 Report Share Posted November 12, 2012 Sorry I had presumed from earlier in the thread that the hull was clean. Slime will easily take speed down and in 4 months you will gain a lot of slime. I see this all the time at work, and our racing yachts would not go more than about two weeks between hull cleans. Its only been a couple of months since Alfresco was last cleaned by a diver and she is already slowing down. Yesterday we cruised at 18 where in that weather at 2500 we normally get 20. Charlie Quote Link to comment Share on other sites More sharing options...
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