Member Removed Posted January 20, 2006 Report Share Posted January 20, 2006 I have bought myself a new Warrior 165 with 70hp Suzuki 4-stroke (nice boat). The motor runs perfect - nice and smooth - but i got some vibrations around 2500 rpm. The dealer says it will stop after the motor is run in - but after almost 30hrs it is still there - a little less - but not gone. Anyone here with a similar problem ? Onslow Quote Link to comment Share on other sites More sharing options...
TomBettle Posted January 20, 2006 Report Share Posted January 20, 2006 Some boats / some engines have what I term (don't know official name) crytical revs. It is quite simply that at a certain revs the engine is at it's least smooth and so anything that can shake will shake. There isn't really an answer apart from steer clear of that RPM. It isn't serious and shouldn't be an issue. Duncan may well have a far more technical explanation and the Warrior owners on here may have an actual solution. Tom Quote Link to comment Share on other sites More sharing options...
Paul D Posted January 20, 2006 Report Share Posted January 20, 2006 I presume the prop has no "dinks" in it and hasn't hit bottom at all - that can cause vibrations. You dont go out of Christchurch I presume Quote Link to comment Share on other sites More sharing options...
Coddy Posted January 20, 2006 Report Share Posted January 20, 2006 Not sure if this has anything to do with it but at the boat show I saw all Warrior boats with a plastic wedge thing, real technical term that, that is mounted on the transom where the engine bolts on. Now my thoughts are that may be if this is not solid you may be getting some vibration from this. I don't have one of those "techy" things on my Warrior so I don't seem to suffer from this problem. Sorry it is not that helpful Coddy Quote Link to comment Share on other sites More sharing options...
Newboy Posted January 20, 2006 Report Share Posted January 20, 2006 Anyone else in the club has a Suzi 70? Quote Link to comment Share on other sites More sharing options...
TomBettle Posted January 20, 2006 Report Share Posted January 20, 2006 Anyone else in the club has a Suzi 70? I have run a Suzuki 70Hp 4s on several of our boats and don't get any probs. They do seem a little noisier than other Suzuki's, but never felt a vibration issue. Coddy, may have the answer with a ding or inbalance in the prop, but unlikely if it has been that way since new. Quote Link to comment Share on other sites More sharing options...
Adam F Posted January 21, 2006 Report Share Posted January 21, 2006 Jimbob runs a 70hp Susi and IMO runs like silk, I havent used it myself enough to establish whether it has thisor not - however as jimbob runs it WOT 100% of the time I wouldnt know!! Seriosuly, my 60hp Mariner on my 165 has this about 4500rpm, it doesnt vibrate as much but the engine pitch goes noticebly louder - a slight reduction either up or down cures it. If it were me I would post on the World Sea Fishing Forum - a couple of the guys have 165's with 70hp susi's. Failing this - go back to Warrior - it doesnt sound right to me. Adam Quote Link to comment Share on other sites More sharing options...
Wedger Posted January 21, 2006 Report Share Posted January 21, 2006 Hi Onslow Not at all my forte but sounds like harmonics / resonance to me. I would look for a minor imbalance. Prop is more obvious but flywheel springs to mind. Chipped teeth on one side or just a bad one. Just because it Quote Link to comment Share on other sites More sharing options...
Guest Guest_Onslow_Fisherman Posted January 21, 2006 Report Share Posted January 21, 2006 Boat, motor and prop is without a scratch. But Wedger is right, i got this plasticthing on the transom. But this a original Suzuki sparepart (!) ( at least i was told). Maybe a should try a woodded plate instead. All suggestions are welcome. Onslow Quote Link to comment Share on other sites More sharing options...
Manic Moore Posted January 21, 2006 Report Share Posted January 21, 2006 It would certainly not seem right, and I would be back to Suzuki. If it is vibrating on a brand new outfit, I would demand it be corrected. I am sure if you are "firm" with them, let them know you are not going to be fobbed off, then they will make some reasonable effort to sort it. Good luck Quote Link to comment Share on other sites More sharing options...
Bob F Posted January 21, 2006 Report Share Posted January 21, 2006 I have a Suzuki 70HP 4 stroke on an Alaska 500. It runs as smooth as silk, except at a certain lower rev (~2000 revs I think) when the boat rattles a little. This is just resonance (the engine revs hitting the same resonant frequency of the boat), and nothing to do with a fault or imbalance in the engine. cheers BF Quote Link to comment Share on other sites More sharing options...
Member Removed Posted January 22, 2006 Author Report Share Posted January 22, 2006 Sorry for my last last reply. English is not my first language - and i had i few Jack D too....( it is cold here, but the salmons are BIG) Bob , do you have this plasticthing between motor and transom that Codfather described ?. Regards Onslow Quote Link to comment Share on other sites More sharing options...
Bob F Posted January 22, 2006 Report Share Posted January 22, 2006 No, there's no plastic wedge. cheers BF Quote Link to comment Share on other sites More sharing options...
Afishionado Posted January 22, 2006 Report Share Posted January 22, 2006 No, there's no plastic wedge. cheers BF The sympathetic resonance that Bob mentioned is well worth looking into. Syn Res happens as he says when the natural frequency of an object is almost the same as an intimate second object. What happens it that object A vibrates at the top end of a sine wave and object B just after the the top of the sine wave thus accelerating the vibration. To cure it may be simple. As an example if one took a 12 " ruler and held it tight to a desk with an end sticking out, then placed any recipricating or revolving motor hard on the desk, by moving the ruler in or out one could find the vibration frequency that made the ruler vibrate the most in sympathy to the motor . Move the ruler in or out and the vibration stops. So try making the vibration happen and whilst it is move the fuel tank somewhere else, move the battery, look at the engine cowling is that vibrating hard, could a small piece of packing stop the frequencies getting in sync, etc. It's worth a try before you do anything expensive. Mad Mike Quote Link to comment Share on other sites More sharing options...
Wedger Posted January 23, 2006 Report Share Posted January 23, 2006 Schoolboy magic . Absolutely priceless........... Quote Link to comment Share on other sites More sharing options...
Newboy Posted January 23, 2006 Report Share Posted January 23, 2006 Ah, but then you are just moving the natural frquency of the boat to a different range, when the rev increases/descreses, it will catch up with it later, however, it might be at a rev you don't use so it's worth a try. Quote Link to comment Share on other sites More sharing options...
duncan Posted January 23, 2006 Report Share Posted January 23, 2006 Scary movie II - I am in total agreement with Mike again! Suspect that the rubber mounting piece is designed to avoid this by creating a buffer between the motor and the hull but transmission could be via steering or even control cables. Worth checking that these are fully secured to the boat etc. Best check is to isolate the engine sounds as best you can; the old screwdriver to the ear/skull bone from engine block for example, and run through the rev range to establish if it is the engine creating the vibration or not. If there is a noticably different vibration from the actual engine at these revs then it needs looking at. If it is the boat creating the 'noise' in harmonic sympathy with the engines vibrations at those revs then just avoid the revs. My money would be on the latter but worth checking. Quote Link to comment Share on other sites More sharing options...
Afishionado Posted January 23, 2006 Report Share Posted January 23, 2006 Ah, but then you are just moving the natural frquency of the boat to a different range, when the rev increases/descreses, it will catch up with it later, however, it might be at a rev you don't use so it's worth a try. Hardly ever if at all Kam. If one were able to look at the sine wave you would see that it would have to go through an almost infinite number of cycles before the harmonics fell into a sequence that would cause further vibration. The point I am making is find out if some simple movement of objects or slight packing between touching components will stop the vibration before throwing money at it. Mad Mike Quote Link to comment Share on other sites More sharing options...
TomBettle Posted January 23, 2006 Report Share Posted January 23, 2006 Reasonance, that is it. That was the word i was looking for in my first post. A way that will sometimes cure it is incredibly simple. You may find this resonance only happens when the engine is trimmed right down hard. Simply trimming out the tiniest amount (the tiniest touch on the trim button)may stop it. Tom Quote Link to comment Share on other sites More sharing options...
Adam F Posted January 23, 2006 Report Share Posted January 23, 2006 Tom, This happens on BW - when the engine is trimmed tight the noise is very pronounced - as you said the mearest touch moves it way and the noise goes - I do this as goo practise anyway as it gives the engine a 'buffer' zone. Adam Quote Link to comment Share on other sites More sharing options...
Member Removed Posted January 24, 2006 Author Report Share Posted January 24, 2006 YES - GOT IT !!!!!!!! In the end of the steeringcable theres a nut ( 14mm head) it was screwed on to tight. In fact this is the only part that have direct contact to the engine. And according to the local Tohatsu dealer you have to screw this nut tight, and then losen it one turn !. It worked !!. Thank you all. Onslow Quote Link to comment Share on other sites More sharing options...
Newboy Posted January 24, 2006 Report Share Posted January 24, 2006 Toharsu? I thought you had a Suzi? Quote Link to comment Share on other sites More sharing options...
Guest Guest Posted January 24, 2006 Report Share Posted January 24, 2006 I have a Suzuki, but the Tohatsu dealer knew how to solve the problem Onslow Quote Link to comment Share on other sites More sharing options...
Newboy Posted January 24, 2006 Report Share Posted January 24, 2006 Nice salmon, where was it? Quote Link to comment Share on other sites More sharing options...
Afishionado Posted January 24, 2006 Report Share Posted January 24, 2006 YES - GOT IT !!!!!!!! In the end of the steeringcable theres a nut ( 14mm head) it was screwed on to tight. In fact this is the only part that have direct contact to the engine. And according to the local Tohatsu dealer you have to screw this nut tight, and then losen it one turn !. It worked !!. Thank you all. Onslow Intimate contact see Always remember when intimate contact causes a problem bring your nuts back a bit Mad Mike Quote Link to comment Share on other sites More sharing options...
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