JIMBOB Posted August 3, 2004 Report Share Posted August 3, 2004 Could do with some advice! Tara has started pulling to the right.I have noticed it getting worse lately. she only does it when on the plane and you can realy feel it on the steering .The speed, if you turn the way shes pulling, picks up buy a knot or two. I have checked round the engine and prop but cant spot any reason for it! Any ideas? Thanks in advance James Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 3, 2004 Report Share Posted August 3, 2004 OK let's go through the obvious which I am sure you have but any way it's worth saying again. Is the engine vertical to the horizontal of the transom? Ditto to an imaginary lie taken from the water line of each side? A new prop with a higher blade ratio causung a 'paddle wheel' affect which will push the stern in the direction of the prop rotation. Uneveness of prop pitch (one blade out of pitch?) Engine in EXACT alignment fore and aft?** A weight distribution problem moving the fuel and the battery to the same side? You've got fatter aswell? ** I've seen this once or twice....... On an older boat the internal wood braceing between the two GRP surfaces of the transom has softend arround on clamp/mounting point but not the other. So when the clamps/mounts are tightened up the transom compresses slightly on one side causing a thrust bias because the engine might be everso slightly off from 90deg fore and aft to the transom. Mad Mike Quote Link to comment Share on other sites More sharing options...
Coddy Posted August 3, 2004 Report Share Posted August 3, 2004 Hi James Have you checked the anti-torque plate fitted to the outboard? Basicly it is a fin which you can move to reduce/remove the torque of the engine/prop. It may have moved, become loose or even droped off! Check all the bolts on the engine mountings are tight. Last alternitive is to slow down so you don't notice it Coddy Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 3, 2004 Report Share Posted August 3, 2004 Hi James Have you checked the anti-torque plate fitted to the outboard? Basicly it is a fin which you can move to reduce/remove the torque of the engine/prop. It may have moved, become loose or even droped off! Check all the bolts on the engine mountings are tight. Last alternitive is to slow down so you don't notice it Coddy By the cringe I bet your right Coddy!! Often these little dodads double as a sacrificial anode, and if that has worn away so it no longer counteracts the engine torque that'll be the answer. Mad Mike Quote Link to comment Share on other sites More sharing options...
JIMBOB Posted August 4, 2004 Author Report Share Posted August 4, 2004 Just looked at the anode fin its is very corroded but tight and in one piece. I think I will just get a new one and see if that helps thanks Guys James Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 4, 2004 Report Share Posted August 4, 2004 Just looked at the anode fin its is very corroded but tight and in one piece. I think I will just get a new one and see if that helps thanks Guys James One has to set it at a slight angle to aim the bow away from the direction its trying to turn, sorta like an aircrafts tail fin. Mad Mike Quote Link to comment Share on other sites More sharing options...
duncan Posted August 4, 2004 Report Share Posted August 4, 2004 Agree the trim tab/anode is most likely cause. One other thing - as the boat will steer to the trim of the engine, ie if the prop shaft is anything other than horizontal there will be a turning moment, have you changed the fore/aft weight distribution of the boat significant;y such that your normal trim settings for the engine when planning aren't achieving this same propshaft angle? Having said that the speed thingy is quite disturbing in that is suggests a more fundamental allignment issue like engine not centred on transom? Quote Link to comment Share on other sites More sharing options...
Newboy Posted August 4, 2004 Report Share Posted August 4, 2004 Having said that the speed thingy is quite disturbing in that is suggests a more fundamental allignment issue like engine not centred on transom? The speed thingy is quite easily explained. It's basicly vector velocity. Assuming the true straight ahead course is the Y-axis, and LHS is the negetive X-axis, and the RHS is positive X-axis. As the boat is travelling at the direction (dictated) by the ob (in this case slightly to the right, say 10 degree). The boat is travelling at 100% (presuming no energy lose to friction etc) of the output, in the direction of 10 degree. Say However, if Jim wants to stay on the [true] course, he has to compensate it with a counter balancing force along the -ve X-axis. Resulting with a slightly less the 100% of output, probably around 92%. Hence the drop in speed. Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 4, 2004 Report Share Posted August 4, 2004 Having said that the speed thingy is quite disturbing in that is suggests a more fundamental allignment issue like engine not centred on transom? The speed thingy is quite easily explained. It's basicly vector velocity. Assuming the true straight ahead course is the X-axis, and LHS is the negetive X-axis, and the RHS is positive X-axis. As the boat is travelling at the direction (dictated) by the ob (in this case slightly to the right, say 10 degree). The boat is travelling at 100% (presuming no energy lose to friction etc) of the output, in the direction of 10 degree. Say However, if Jim wants to stay on the [true] course, he has to compensate it with a counter balancing force along the -ve X-axis. Resulting with a slightly less the 100% of output, probably around 92%. Hence the drop in speed. Well we all knew that anyway, 'sobvious innit! An' in practical applications of your formula you gotta take asymetric velocity vector due to varying drag coefficients into account any road up innit! The big question is answered easily by getting Victor to stand on the other side of the boat or leave the bugger at home for causing all this trouble anyway innit! Mad Mike Quote Link to comment Share on other sites More sharing options...
duncan Posted August 4, 2004 Report Share Posted August 4, 2004 Thank you Newboy.......I didn't intend to show surprise only concern. My reason for the latter is that something in his setup has to be fundamentally wrong if he is obtaining more speed in other than a straight line, whereas other forces could come into play in a number of ways to create the turning moment but you would expect all of these to deliver a reduction in speed. Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted August 4, 2004 Report Share Posted August 4, 2004 Mike Which gull are you would it be the one on the right Martin Quote Link to comment Share on other sites More sharing options...
Afishionado Posted August 4, 2004 Report Share Posted August 4, 2004 Mike Which gull are you would it be the one on the right Martin To quote the motto of the Guards........ 'honi soit qui mal y pense' (evil is he that evil thinks) I would sugest I could be thought of as either depending on the generousity of ones nature. Mad Mike Quote Link to comment Share on other sites More sharing options...
Swainiac Posted August 5, 2004 Report Share Posted August 5, 2004 Mikey...............I always thought that the literal translation was Honest sweat makes smelly pants...........must be wrong!!!!! Rich Quote Link to comment Share on other sites More sharing options...
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