while the outboards may be able to handle it I have seen many fuel lines and primer bulbs distroyed from ethanol. This in turn goes into the engines fuel system and causes havoc.Originally Posted by Noelm
while the outboards may be able to handle it I have seen many fuel lines and primer bulbs distroyed from ethanol. This in turn goes into the engines fuel system and causes havoc.
And there is a big part of the problem. Yamaha are not the only manufacturer to do this. It is not until you start to do some research that you find out it is better for the engines to be at or towards the top end of the WOT rpm spectrum. BRP as an example also have a quite wide WOT band for there motors, but if you dig deep enough there is also an "Optimum RPM" chart that is really the one to achieve that only has a typical rpm variation of a couple of hundred revs.
The optimum rev range is right at the peak of the torque curve.
However unlike cars which have variable gearing, boats by design must operate under load outside this range (and indeed WOT) as we only have one gear for all conditions (usually)
We all get that correct propping will result in optimal speeds vs load, but it's a cop out to say that this failure was caused by propping.
If they're that sensitive we should be propping to achieve max RPM at less than WOT as that will reduce load (at the expense of speed)
Cheers,
Owen
The whole world's mad save thee & me (but I'm not too sure about thee)
Regarding the issue of engines operated in a way that causes "lugging", I've just spoken to a friend who is a professional engine builder and asked the question. He explained it like this:
When an engine is operated under excess load, in effect the engine is trying to push the crankshaft one way, and the load coming back thru to it from the gearbox is pushing the other way. So this loads up the crankshaft bearings, conrod bearings and even the rings. The engine entries to overcome this load by adding more fuel, advancing the timing and this increases heat, and may also cause pre-ignition which is bad for Pistons, rings and causes excessive carbon build-up. If done for long enough the combination of load and heat can result in fuel getting past the rings and into the oil, diluting it and reducing its lubricating capacities.
The greater the load, the more wear and stress on these parts as the engine tries harder to overcome the load. According to him, this is even worse for the engine if the engine is new and is run-in under such conditions.
He said the excess wear and damage caused may not be immediately apparent, but it has nevertheless reduced the life of the engine or can contribute to the early failure of any of the engine components from the bottom end thru to conrods and Pistons.
Now we don't know what has occurred to Buggsies Yanaha. Hopefully the strip down will reveal all!
It does seem like it may have not been optimally propped by the previous owner, a situation Buggsy remedied immediately. But possibly the damage may already have been done, as it was with my mates Yammy 250hpdi.
But anyway, there you go, that's what happens to engines thatto are constantly lugging.
Note to self: Don't argue with an idiot. They will only bring you down to their level and beat you with experience....
Port motor went "Bang" during first or second sea trial and was swapped out completely by Yamaha. It had under 10 hours on it. It would seem five years later it's partner motor went bang with 380 hours on it.
It also begs the question what happened to the Port motor with only 10hrs on it............. What happens on the inside of an outboard engine during operation is like coming up with an explanation of the universe. Jim
Haines Signature "FinaLeigh" 580F 135 Optimax
CH 81 & 72 VHF
moonlighter, that's a pretty spot on post from my perspective,"lugging" is the absolute enemy, especially in run in period on any engine !
the ramifications down the line can be immense.
I've never fully re-built an out board engine "completely" but have probably rebuilt at least a dozen or so bike engines, albeit classic motors.
I can tell you, idling them around and lugging them during break in causes havoc with them in regards to ring bedding, cam surfaces and the list goes on. Its not a factor with regard to rev's as much as the load the motor is under, if an engine can not reach its maximum specified rev's its doing so because of incorrect load, increasing loads on other motor parts that weren't designed to do so, now this may be because of gearing for a motor vehicle or Propping as per the current subject. I have no issues immediately going to 2k rev's from actual first start up on a re - built engine, statically time the engine only before riding it ( as the electronic ignition requires at least 4k rev's to time electronically), the whole time eliminating any "Lugging" what so ever and even red lining within the first 50 k or so.
So, in short, I've seen what lugging a new engine does to it inside from the start, it's detrimental to its efficient break in and subsequent longevity right from the start, you have to take that right thru an engines life, for a boat engine, incorrect propping hurts the motor !
at the end of the day as moonlighter sais, buggsies noticed and rectified the apparent issue with the props, but as mentioned, how much damage was already done. Again, we only summise until a full strip down has been done and even then it may be hard to diagnose the actual reason for the failure, maybe its totally unrelated, but if it subsequently prompts someone else after reading this thread, that has doubts about there own motor or propping, to save them an issue down the track, then the best piece of advice I read on this thread, wast to find out the max rev's for the engine and prop accordingly, just makes for an easier life for the motor and that means dollars saved....
just my opinion
bonneville
They seem to be a Monday morning/Friday afternoon motor for some reason if you get the wrong one. Hercules on here had one go on him under the warranty period. I am very familiar with Buggy's boat and Dolphin Marine were actually aboard when the first motor went at 30-40hrs and it was replaced no questions asked.
I had a F150 and sold the Stabicraft with it on the back at 900+ hours. I was slightly overpropped if I remember correctly. Solas had a limited range for them at that stage. I am pretty sure mine ran a 18" 3 blader. It used to pull 37knots for 61 litres an hour at WOT if I remember correctly. My prior Johnuki 140 was overpropped as well slightly and once again there was too much of a gap in the Solas range to get it 100% spot on but it developed a cracked head at 2,400hrs but that seemed a bit of a thing on those motors pre billeted aluminium heads. At 600hours on my F150 I developed a small vibration at dead slow idle of 600rpm on the electronic tacho. Bump it up to 650rpm or 700rpm when slow trolling livies and it dissappeared. My mobile mechanic could never find out why but it was not there for the first 600hrs or so but was there after. I rember Stealth the big Seastorm platey putting in beside me one day with twin F150s and I thought he had the same vibration on one of his but not the other.
I didn't think there was anything majorly wrong with Buggys Grady. I did a three dayer on it to the top of Breaksea out of Mooloolaba one trip and quite a few days/arvos on it. The F150s were certainly better than the 2 smoke 225 EFI Yammies it had on it prior!
Are you someone's wife
I also have another 12 foot tinny - I'm up to 5 boats in total but my goal is 7 - one for every day of the week.
I appreciate the comments from everyone so far. I'm interested in the lugging theory - that will be very hard to proof however.
No-one has really spoke about the the F60 - other than the earlier conjecture around the oil pump. I've had that from new and its been propped fine from day one. Might just be bad luck.
The big cat might take a while before Gary gets a chance to take a look at it so we may have to hang around for a while for the proper diagnosis. Hopefully the F60 will get pulled down in the next week or so.
Brett
I think im havin a man crush ! 5 boats LOLAre you someone's wife
I also have another 12 foot tinny - I'm up to 5 boats in total but my goal is 7 - one for every day of the week.
listen good luck with the motors bugman, Im feeling the pain for you !
be really good if you do end up finding out the reason why and it may help with your re-power etc
just a damn costly exercise !
bonneville
No Its all good. Its a Honda. It will go for years no worries
Any news on the engines yet?
Dan
Confidence.......the feeling you get before you fully understand the situation.
Yes, what you have heard is bullshizen. Furthermore, to say one brand does it and the other does not, its also rubbish. The fact is, that 90% of your fuel is shipped was shipped from 2 refineries, and now only one. Its only when the refinery cant meet local demand that fuel is shipped from interstate refineries. If it has ethanol, it will be stated by the servo selling it, this is law. I believe that servo's are subject to random testing to ensure compliance (just as they are randomly tested to ensure accurate delivery)just a interested query - in the past I have been told both 98 and 95 octane fuel has a significant percentage of unadvised / unpublicised ethanol in it (as just under the designated 10 % content ) and allegedly with BP and others majors in particular - my local Caltex guy says there is no ethnol in the Caltex 91 fuel - not sure about there 95 and 98 so I do stick with the 91 Caltex brand fuel in my merc 4s 60 hp big foot - hate ethanol and the risk it poses to a OB and the fuel lines etc
any other informed comments re for or against that ??
cheers rob
Furthermore, unless you are running a high compression engine, then buying high octane fuels is simply throwing away your hard earned. The octane rating is nothing more than a measurement of the fuels ability to resist detonation. You dont get better, cleaner fuel and you certainly dont get more power. In fact, given the turnover or regular 91 octane fuel you will most likely find its the freshest fuel that the servo sells. About the only difference you may find, is that some higher octane fuels will contain additives that supposedly clean your engine, but I reckon this may just be marketing drivel.
I run 98 in my motor and I get better economy and it defiantly burns cleaner as it is more refined than 91. I personally think it's better for your engine. I agree 91 won't destroy your engine, but it's deffinlty not gonna hurt running a more refined fuel.
Higher octane fuels will give you some improvement in economy, mostly, apparently, due to slightly higher density I am told, which means more energy per $ because it's sold by volume, not mass. It is a measureable difference. Whether this offsets the extra cost to buy it is the thing to figure.
The cleaning additives are real, and will mean better results due to things not getting gummed/clogged up. Of course, you can buy 91 and add your own additives, or even, just service the motor more often to keep it clean - it's all just a matter of figuring out which costs less per hour of running when you figure in ALL the costs.
I once did the sums on a small hyundai car, and I figured it at least broke even. I have a feeling that, as time drew near to have the injectors cleaned, it was still running better, and that probably made using 95 instead of 91 worthwhile.
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