Adam F Posted September 15, 2004 Report Share Posted September 15, 2004 Took Bw with her new engine out today to 'run-her' in.... Read the book and it gives the same as Coddy suggests: 1st hour: Not more than 3500 rpm - vary throttle 2nd hour: Not more than 4500 rpm - vary throttle, and give full throttle 1 min in every 10 next 8 hours - full throttle for not more than 5 mins at a time. Did 3 hours today - but as I have never run a new engine in before what should I expect??? The run out to the spoil grounds took 1 hour at 6 knots, I then tried to increase to 4500 rpm, but 4000 was max, after a while it seemed to loosen a little and 4500 was possible. Coming in we managed 5000 and about 20/21 knots, but this took a while to reach. The 'hole shot' to get up onto the plane seemd very slow also? Coddy gets 26 knost from the same boat and engine??? Do engines take a while to loosen up? Is this normal? Could I have too big a prop? Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted September 15, 2004 Report Share Posted September 15, 2004 Adam Did you trim your engine out? if you did it sounds to me as though you might be over proped. Take a look at your hand book and it will give you the rpm that your motor should run at flat out. You need to get as close to this as you can for optimum performance and economy. If you cant get near this then have a word with Tony, he should be able to exchange the prop for you. Martin Quote Link to comment Share on other sites More sharing options...
Coddy Posted September 15, 2004 Report Share Posted September 15, 2004 Hi Adam My boat/engine was second had but had only done approx 28hrs in 2.5yrs!! I have to say my engine has faster response now, 71hrs, than it did when I first got it so I would suggets that like a car engine it will take some time to run in properly. Can I suggest that you keep a record of hrs and miles used with the amount of fuel used each trip and we could then compare. I seem to have read somewhere that it should have a service after 25hrs but can I find that info? I would stick with the prop you have as the revs and speed seem the same as mine. I would agree that it does not 'jump' on the plane but builds gently but at 20kts it is sooo comfortable. Good to hear your back on the water Coddy Quote Link to comment Share on other sites More sharing options...
Newboy Posted September 15, 2004 Report Share Posted September 15, 2004 It wouldn't surprise me if an oil change is needed at the 1st service, usually new engine needs much finer oil to lube the components and as it ran it, they change it to a thicker oil. It might be worth while to use the best oil you can afford, full synthetic if they do it, they protect the engine like nothing else. Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted September 15, 2004 Report Share Posted September 15, 2004 Adam With modern engineering tolerances engines should spin freely when they are first fired up and should be performing near their optimum almost straight away. I would reiterate that your engine should be able to run at or near the recommended max revs. if your engine doesn't and you are over-proped you could put excessive strain on your motor causing long term problems with worn out components. The symptoms of over-proping are slow onto the plane, not being able to reach the full rpm, not reaching the max top speed and possibly higher fuel consumption. Your engine also will not develop its full hp until the optimum revs can be achieved. When I got my new engine it did not get to the full revs with the prop supplied. Bearing in mind my engine is a 150hp and after owning boats with 50hp engines it still seemed fast to me. The engine was only achieving around 4800rpm when the book stated it should run at 5600rpm give or take 200 rpm. After going to Warrior and achieving nothing I went to propeller revolutions and Tom there stated that the prop was my problem have one of these, and so I did. Wow chalk and cheese is all I can say to explain the difference. I kept my old prop as a spare and earlier this year I put it on and gave it a go, sure enough slow hole shots and only achieving 4800 rpm Maverick was like a slug. I soon changed back again. If your worried have a word with Tony at select and put your mind at rest or failing that go and see Tom, give him the boats spec, he will calculate the correct size and pitch of prop for you. Fun this boat owning lark isn't it Martin Quote Link to comment Share on other sites More sharing options...
Adam F Posted September 16, 2004 Author Report Share Posted September 16, 2004 I think I have to agree with Maverick - all the symptoms I mentioned yesterday are the same..... Tony is on holiday now for 3 weeks - will I be able to run the engine easy until then without any problems?? Coddy what prop do you have?? The engine comes with a free 20 hour service. The engine, gearbox and hydrolic oil is all changed and the engine is plugged into the computer via the ECU to check its performance. If I go to Tom, what will a nw prop cost me? If I wait until Tony comes back wil he change the prop FOC?? Quote Link to comment Share on other sites More sharing options...
Malroy Posted September 16, 2004 Report Share Posted September 16, 2004 At first you may be a little dissappointed with the cold start performance of the 4 stroke, i.e. a short warm up period coupled with slower acceleration than the 2 strokes. My Honda will also stall if I wap the throttle fully forward quickly, I have to be less aggressive on taking off than when I last had the 2 stroke. Don't know if other 4 strokes behave like this, I would be interested to know. Once the engine loosens up, this will improve a bit. The advantages of the 4 stroke will far outweigh this e.g. better idling, quietness, fuel economy, low speed trolling ability etc, etc. As with most 4 strokes it will take around 20 hours plus to loosen up enough to pull full revs. Try not to be too eager to get there during this period at first. What you are doing in building up the revs gradually in varying length busts is right. When you start coming close to max rev achievement, limit the periods of max bursts until it is fully loose. During this period I would not advise playing around with prop pitches unless your existing one supplied is already known to be too high, as others have mentioned there may be a risk of undue strain on the engine. Quote Link to comment Share on other sites More sharing options...
Coddy Posted September 16, 2004 Report Share Posted September 16, 2004 Coddy what prop do you have?? If I go to Tom, what will a nw prop cost me? If I wait until Tony comes back wil he change the prop FOC?? Hi Adam You have got me going regarding my prop size. Went out and checked the boat but no size was printed on the prop only a ref number 48 73136 A40 13P Did a serch on the web and found this site http://www.propline.com/Select-Boat-Props-...50_4_Stroke.htm It turns out to be a Mercury Black Max Aluminum 3 blade 10 3/8 Dia x 13 Pitch As mine is not the BigFoot model you have got me wondering now, 'What if I changed my prop' but the rev range on WOT is just under 6,000 rpm which is what the book says! Be interested in your prop size. I do not expect you to be able to swap props FOC once it has been used Regards Coddy Quote Link to comment Share on other sites More sharing options...
Paul D Posted September 16, 2004 Report Share Posted September 16, 2004 Malc, My Honda BF30 doesn't quite stall if the throttle is opened up suddenly but it attempts to !!. Hearing yours does the same I now feel much happier Quote Link to comment Share on other sites More sharing options...
Adam F Posted September 17, 2004 Author Report Share Posted September 17, 2004 Interesting!!!! I have a 48 73138 A40 14P on the new engine which according to the link you posted is a 10 1/4 x 14 pitch. The prop form the old 50hp is the same as the one you have, so I have 1" extra pitch on the new prop....the plot thickens. I can get about 5250 Rpm at the moment on the engine which has done 3 hours, so I rekon that the smaller prop would give me WOT 6000 rpm... I think Ill whip the new prop off and try the old one - if it works, when Tony comes back Ill exchange the new prop for a 13 pitch, and then Ill have 2, 1 as a spare. Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted September 17, 2004 Report Share Posted September 17, 2004 Each inch of pitch equates to approximately 200 rpm Quote Link to comment Share on other sites More sharing options...
Adam F Posted September 17, 2004 Author Report Share Posted September 17, 2004 WOW!!!! Whipped the new prop off this morning, and bolted the old 13" jobbie on. Anyway, sat in the office workign with it lashing with wind and rain outside, and curiosity got the better of me (impatient more like) so in a rash decision, BW was soon hooked up and Im off to Wick to test her out. What a difference!! So much snappier on the throttle, she now surges at even the slightest touch of the throttle, snappy hole shot - AND.......I stopped at 27 knots, as I scared myself! The harbour in xchurch was deserted due to the F6 SW and rain, even so it was pretty damn choppy. I opened her up to about 5250 RPM, and at normal tilt (down) she hit 27 knots. I reckon 30 will be a possibility with 6000 rpm and the engine tilted! This was also the 1st time Ive been to sea completely alone. I wore a jacket of course and took the aux engine - but its a strange feeling being out at sea all alone! There was a huge swell running and it wasnt too nice - hengistbury head gave a little bit of shelter, so I only stayed out for 1/2 an hour playing in the waves!!! Anyway im deleriously happy with the new engine and the way she performs!! Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted September 17, 2004 Report Share Posted September 17, 2004 Adam Nice one mate glad that we (the forum) sorted your little problem out and that your new shiny bit of metal does the biz. So, will I have to watch you shooting over the horizon or will I be able to keep up with you Just one thing, make sure that when you have the courage to open her right up and trim the engine out that the rpm does not exceed that recommended by Mariner. Martin Quote Link to comment Share on other sites More sharing options...
Paul D Posted September 17, 2004 Report Share Posted September 17, 2004 Adam, Pleased to hear the new engine is going well now. For one moment I was beginning to think there could be a chance I would be able to keep up with BW but not now eh ! Quote Link to comment Share on other sites More sharing options...
Coddy Posted September 17, 2004 Report Share Posted September 17, 2004 Hi Adam Glad to hear the engine was better You got me thinking as well ......... is my prop too small? Seems not so Hope you are still keeping a log of all the trips (miles) hrs run and fuel used, makes interesting reading on how the bank balance has disapeared Only thing now is will a Stainless prop be any differant? From what I have read they seem to think it is more efficent! Any members with aluminium to s/steel experiance? Regards Coddy Quote Link to comment Share on other sites More sharing options...
Paul D Posted September 17, 2004 Report Share Posted September 17, 2004 I almost bought a stainless prop but was advised against it, since the likelihood of clipping the bottom coming out of Christchurch harbour is significant and with a stainless prop this is less likely to be the weakpoint ( ie. gearbox gets damaged as opposed to propellor ). Quote Link to comment Share on other sites More sharing options...
duncan Posted September 18, 2004 Report Share Posted September 18, 2004 If the bottom you expect to clip is shale, gravel, sand, mud etc then a stainless prop will be a significant advantage for the following reasons - 1. the above won't damage it 2. stronger material enables thinner blades which are more efficient 3. stronger material doesn't flex as much 1. don't keep needing to replace/repair prop and you will always be able to 'plane home. Interestingly you can do much damage to a gearbox running back home on a damaged alloy prop.......... 2. faster and more fuel efficient 3. smoother with a 60hp you should see all the above advantages you should be able to get one second hand for a Mariner and not much more than 100 new. Quote Link to comment Share on other sites More sharing options...
Afishionado Posted September 18, 2004 Report Share Posted September 18, 2004 Duncan is absolutely right and there is very little danger of damaging the gear box as the rubber hub bush acts as a weak slipping link allowing the prop' bush joint to slip well before the shear point of the gearbox teeth. I think that more harm is done to final drives gears and bearings by out of balanced bent and chipped props than anything else. Mad Mike Quote Link to comment Share on other sites More sharing options...
Paul D Posted September 18, 2004 Report Share Posted September 18, 2004 Interesting. I was going to get a stainless one and was told this by the dealer. Mind you, I am not so sure I could afford a stainless one at the time anyhow !! Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted September 18, 2004 Report Share Posted September 18, 2004 Duncan is correct on all counts. The bigger the engine the bigger the benefit. Stainless props dont bend so no loss of performance due to flexing. You may notice a clunk when you put your engine into gear, this is normal. The best way to minimize this is to be positive when shifting into gear ie put it straight into gear and not try and eaze it in. The only thing I would dissagree with is the price of stainless props. A new stainless prop for my 150hp was Quote Link to comment Share on other sites More sharing options...
Adam F Posted September 18, 2004 Author Report Share Posted September 18, 2004 Is it worth me looking at one for me 60? Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted September 18, 2004 Report Share Posted September 18, 2004 Adam I wouldn't rush out and get a stainless prop if I were you. The performance benefit on a 60 will not be that noticable, the durability is worth considering though. Certainly keep your eyes open for a second hand bargain. Martin Quote Link to comment Share on other sites More sharing options...
duncan Posted September 18, 2004 Report Share Posted September 18, 2004 Martin I was basing the price on one purchased 2 months ago for an Alpha One drive - which is I think the same fitting etc. Next time I speak to the guy who bought it I will find out where he got it. I agree the performance benefits are bordeline on a 50/60 but if there are 2 boating areas I would want one they are Poole Harbour and Christchurch! Quote Link to comment Share on other sites More sharing options...
Bob F Posted September 18, 2004 Report Share Posted September 18, 2004 If you do buy a S/S prop, don't buy one that is the same size as your Aluminium one. With S/S the prop needs to be smaller. Or at least this is what the Suzuki dealer told me. Malroy, Paul, I've never had any problems with cold starting on my Suzuki 4 stroke, or a tendancy to stall when cold. Are your engines carbs or electronic injection? Bob F. Quote Link to comment Share on other sites More sharing options...
Newboy Posted September 18, 2004 Report Share Posted September 18, 2004 Just wondering, are all propellers have same fitting or do they vary from different brands? Quote Link to comment Share on other sites More sharing options...
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