I had problems here in Townsville with my 2 stroke 130 yamaha....boat stored outside under a tarp....used to have problems starting but ok when she was running....even when boat was used within the 2 month period mentioned. Yamaha dealer who serviced the engine told me that fuel quality was pretty poor these days and really didnt last up here I think most things deteriorate much quicker here in the tropics......
Gelsec it is my understanding that the warmer/more humid the climate the more rapidly fuel will deteriorate.
Cheers
The fuel companies will never guarantee fuel quality, even if it's one day. Can you image the legal remifications????. So really 3 months is guessing???. Look at the car yards. I don't think they drain their fuel every two months or so???. What about big cruisers??????.
The US kittyhawk with jetfuel, i don't think they drop by a petrol station every two months and fill up do they????????.
I have never seen anything in writting about fuel going off. Just recommendations.
Boat yards?? do you see them taking old fuel out????
another senario is petrol stations. If there is higher demand for petrol in one certain day, you may be the bugger putting crap fuel from the bottom of their tanks????
For the 3 yrs I sold used boats I did not let a boat leave the yard with old fuel.Originally Posted by timddo
I think you will find that fuel onboard an aircraft carrier is stored sealed and in a temperature controlled environment thus lasting longer.
A service station will get fuel delivered weekly so its turning over its fuel very quickly. It to is in a temerature controlled environment to a degree. It does not get the extremes of temperature that it does above the ground.
Last edited by BM; 12-08-2007 at 09:26 PM.
I was told by Rising Sun Marine in Townsville that fuel deteriorates much faster in warm climates.
The Mechanics there also showed me a half 44 gallon drum full of farked pistons they were keeping for the aluminium scrap metal. Guess what, most of them had holes burned in them from stale fuel (some guys with the blown motors said their fuel was not older than 8 weeks from the bouser).
The biggest problem on top of the heat in northern places is that if you buy fuel and keep it for 4 weeks, it may actually be 8 weeks or more old already due to extended shipping times etc and slower turnover of the fuel where you buy it.
I do not personally use fuel older than 4 weeks. This might sound pedantic, but this is best for me because I have a 4 week opportunity to use the boat and then next 4 weeks where I can't. 8 or 9 week old fuel when I get back is way too old for me to be happy with it so it ends up being pumped out of the boat and used in the car before I fill up the boat tank with whatever I need.
I can notice the difference in WOT revs between new fuel and older fuel.
Like some of the gents above have mentioned earlier, fuel is simply not made the way it used to be and does not last as long as it used to. And remember that the shelf life of the fuel begins when it was piped out of the refinery, not when you pumped it into your tank at the bouser.
Cheers
Mick
Big cruisers are fuelled with diesel. Biggest problem with older diesel fuel is algae growth (Needs a biocide additive to stop this if sitting a long time) and loss of centane rating. (Diesel is rated in centane not octane like petrol). Diesel engines can run on a wide variety of oils and the age of the oil is far less critical compared to a finely tuned petrol outboard engine.
Jet-A1 fuel used in aircraft is an oil as well, similar to kerosene but more highly filtered and refined. The aircraft engines are turbines which are completely different to petrol engines.
and yes, you can get some horrible crap from the bottom of a petrol station tank... cost me about $450 to get the tank cleaned, filter changed and carbies fixed 6 months ago when it happened to me. Slimey gunkey gritty shite came out of the tank and fuel filter and also clogged up the carby jets. Luck of the draw at your servo...
An petrol outboard engine is a highly tuned precision engine, in which it is far more critical to have 'perfect' fuel.
cheers
Mick
Last edited by trueblue; 12-08-2007 at 10:06 PM.
Rising Sun marine?
Even though Kerry is sometimes a pain in the Ar$e, he is also very often correct.. In the old days, you were advised to "keep your tank full" to minimise water intrusion and keep your fuel longer by using additives. But with boats now having water separators and no real evidence of fuel life available, I tend to disconnect the fuel line from the motor and remove the fitting. I use a 2nd bulb to remove as much fuel as possible after about 2-3 months (put in company car) and leave the tank near empty til i'm SURE that the boat is going out in a few days. This was on Kerry's logical advice.
Well call me a skeptic, but until i have actual proof, 100% undeniable proof, before my eyes, my habits will not change.Maybe a job for Mythbusters,get 100 litres of fuel, get its octane numbers prior to test, and leave it in container for 6 months and get a QUALIFIED TECHNICIAN to ascertain the difference in its octane numbers..Then and only then will the vast majority of neysayers like myself hede the advice. But as yet no one to my knowledge has done such a test. To me,2 months is stupid,but thats just my opinion as others have there's to which they may well think im stupid.
When one has seen 13 (that is thirteen) engines of several makes all siting on the one bench, at the one time, all with almost the same identical hole in the top of the piston (mainly #1) then you really don't need to be a QUALIFIED anything as it's quite simply all before you and any mug who would then go and run their engine on old fuel simply deserves all they bloody well get and hopefully what they deserve!
So of these 13 engine did they all buy there fuel at the same time and did not use it for 2 months? Or did they all buy there fuel from the same contaminated Servo ? Were they new motors or old, 2 or 4 stroke? Exactly how long had each owner left there fuel un- used for? Do you know the circumstances of the whole 13 engines, or were you just summising? Anyone can go into a workshop and see engine's being repaired, where's your proof Kerry, your pretty big on proof!!
Kerry, BM, et al,
Might I ask are your recommendations re stale fuel directed mainly at two stroke outboards, or four strokes and stern drives as well?
If it is a problem with four strokes also, how come it is O.K. to put it in your car?
I am running a 4.3 litre MPI V6 Mercruiser, do you think the same recommendations would apply to this engine?
Richard.
All the proof you'll need buddy is a hole in #1 and until that time I doubt you have the capability to understand or want to understand what this is all about.
As BM previously stated their is no future in discussing this matter as some of you characters still wouldn't believe it when fate catches up with you and there's a big enough hole you can shove your nose up.
Regards, Kerry.
Kerry as i thought, my cousins uncle's brothers dog tin tin overheard a guy....For a guy who wants proof all the time, but does not supply it when he's asked, well....... So i take it you have no knowledge of these 13 engines, except what some guy told you ?? Oh well you've converted me with this here say evidence
Last edited by fishing111; 13-08-2007 at 01:09 PM.
Instead of arguing, there is an easy way to prevent the problem, DON'T LEAVE FUEL IN YOUR BOAT!!
If you have surplus fuel after a trip drain the tank into your car, this way, next time you take the boat out you will be using new fuel from the bowser and by using the surplus fuel in your car in a smaller time frame, your car's engine will not be at risk from stale fuel.
I wish people would read between the lines, is not about only taking the exact amount of fuel out with you, its about what you do with the surplus, so just use surplus fuel either ASAP in your boat on another trip or put it straight into your car.
If you have 2st mix don't fill a full tank if you are not going to use it all, when you plan a fishing trip try to plan a few in succession so you use all the fuel over a couple of trips and minimise waste.
As to the initial quetion which started this thread, If in doubt, drain the tank and use new fuel and if there is any residual stale fuel left over don't go too far out, if you engine does fail, you don't want to be stuck 20km off shore.
Last of all, everyone has their own preferences, and which ever way you choose, only the owner/user of the boat will be paying for any extra spent on new fuel or repairs, each to their own, everyone learns from mistakes no matter what the cost.
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