Fisherman Rob
Well-Known Member
Is it worth putting premium fuel into a 1996 2 stroke Yamaha 115?
Premium fuel for 2 stroke?
- Thread starter Fisherman Rob
- Start date
Fisherman Rob
Well-Known Member
Googling around it seems the general consensus is that it make no difference. Might as well use 87 octane.
fishin_magician
Well-Known Member
Depends.
I ran a Merc and premium Chevron 94 definitely gave it more responsiveness and more grunt. The computer was basically advancing the timing more aggressively. More advanced timing=more power and a lighter wallet.
I ran a Merc and premium Chevron 94 definitely gave it more responsiveness and more grunt. The computer was basically advancing the timing more aggressively. More advanced timing=more power and a lighter wallet.
Hookin'up
Well-Known Member
Be carefull with oxygen enriched fuel and 2 strokes
I remember back in my dirt bike days being told that it burns them(pistons)up quick,
I just tried to find something on it and cant seem to
but I do remember it wasnt an issue running high octane but the additives in the higher octane fuels
counter-acting with the 2 stroke oil causing lubrication issue or lack of,
hopefully somebody can chime in and either deny or confirm
I remember back in my dirt bike days being told that it burns them(pistons)up quick,
I just tried to find something on it and cant seem to
but I do remember it wasnt an issue running high octane but the additives in the higher octane fuels
counter-acting with the 2 stroke oil causing lubrication issue or lack of,
hopefully somebody can chime in and either deny or confirm
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Fisherman Rob
Well-Known Member
Actually I was wondering about that. Is it cheaper to buy fuel at the dock?
Bent-Tip
Well-Known Member
trendsetter
Active Member
No reason at all to run premium in that motor. It won't hurt it, it'll just cost you more. Those motors do not have computers that sense engine knock and retard/advance timing. The compression also isn't high enough to require >87 octane. Just run 87 or the marked 89 if you can find it.
The only benefit to premium gas is if it's ethanol free, such as Shell vPower 91 octane. And then it's only beneficial if you are leaving the boat for extended periods of time (3 months pus) with fuel in it.
The only benefit to premium gas is if it's ethanol free, such as Shell vPower 91 octane. And then it's only beneficial if you are leaving the boat for extended periods of time (3 months pus) with fuel in it.
trendsetter
Active Member
Bob was right in that it won't hurt your motor, just your wallet! lol. They all have aluminum pistons and they run just fine on the octane rating recommended by the manufacturer. Save your cash and run 87 unless the manufacturer of your motor recommends otherwise.
Drewski Canuck
Active Member
Real issue is the Ethanol. Some 87 Octanes can be 15 % ethanol. Older motors may have the gasket material in the carbs that softens from ethanol. That is the issue. Small engines such as trimmers and chain saws can really get cooked from the ethanol sitting in the carbs for weeks on end. Too expensive to justify fixing it, so you throw it and buy a new one, when the only problem is a leaky gummed up carb that costs as much as the equipment once the shop is done with you.
Drewski
Drewski
trendsetter
Active Member
Typically, in Canada, gasoline is 10% Ethanol for 87 octane, 5% for 89 and 0% for 91. This is because there are only two grades of fuel commonly refined; 87 and 91. 89 is a 50/50 mix of 87 and 91. It's either mixed in the pumps or mixed by the fuel truck as it unloads to make 89.
Some stations, like Mohawk have up to 10% in all their grades. Either way it should be labeled on the pumps. Any fuel that contains 15% ethanol has to be marked as E15 as not all motors are compatible with 15% ethanol mixes.
In 4-stroke engines there is always a small amount of fuel that gets by the rings and into the crankcase. There are additives in the oil to help neutralize it but that is also one of the reasons it needs to be changed often. The dye in the marked fuel just makes it easier to see.
sammyslabber
Active Member
Co-op marked gas is another reason to shop there;well shopping local, shares & 5% kickback helps too...
I did notice a little leftover dye residue in my old I/B intake manifold; not sure that matters?
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Fishin'Zinn
Active Member
I have noticed a difference with gasoline blended with ethanol additive... if you are a gearhead, you probably know that in a lot of cases now it can be less than preferential. Whether it be a Newer outboard or an old carbed smallblock chev, you notice a difference with 94 octane compared to gas with ethanol in it (At least for engines made before blended fuel came around). Runs slightly differently, less responsive, etc.
For modern day cars it is different however, many are compatible with it and makes no damn difference. However with different/less 'advanced' technology in marine engines, a lot of things are prone to the corrosive properties of ethanol (injectors which aren't compatible, rubber fuel lines, etc), especially in older outboards. So be careful with that. In the long run, will it really make a difference? probably not. Just something to consider...
Curious to know if Marked gas is Ethanol free? I would bet it is, but am unsure here.
For modern day cars it is different however, many are compatible with it and makes no damn difference. However with different/less 'advanced' technology in marine engines, a lot of things are prone to the corrosive properties of ethanol (injectors which aren't compatible, rubber fuel lines, etc), especially in older outboards. So be careful with that. In the long run, will it really make a difference? probably not. Just something to consider...
Curious to know if Marked gas is Ethanol free? I would bet it is, but am unsure here.
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Busterbrown
Active Member
The ethenol content in regular gasoline in the lower mainland is 10% .It is the same in some midgrade fuels at service stations. There is no ethenol in supreme or supreme plus. The midgrade fuels at marinas currently have zero ethenol in it.There currently are no plans to change that.That is one of the benefits of purchasing fuel at a marine location. The ethenol component of gasoline and the bio component of diesel is a very good effective cleaner,unfortunately a lot of marine equipment is older and subject to having seal and gasket failure with ethenol.In addition the fuel lines and tanks are scrubbed clean and filter clogging was a concern when B5 diesel was first introduced.We had many customers haveing to change fuel filters many times until the fuel delivery systems were cleaned up.
The dye in gasoline does make its way into the crank cases of 4 stroke engines trough fuel dilution but it will harm nothing just looks very red .Yamaha engines seem to be more prone to having fuel in the crank case
The dye in gasoline does make its way into the crank cases of 4 stroke engines trough fuel dilution but it will harm nothing just looks very red .Yamaha engines seem to be more prone to having fuel in the crank case
finaddict
Well-Known Member
I think that may be due to trolling speeds when the engine never really reaches operating temperature, so it does not fully burn the fuel during the power stroke
finaddict
Well-Known Member
Thanks TS that was very informative and good to know.
Seafever
Well-Known Member
Yes...they call that "making oil" in four strokes......you run the engine for some hours and you notice the dipstick level is higher than it was before.
Happens when you run the 4-stroke for periods and it doesn't heat up enough.......then the blow-by mixes with the oil and increases the volume.
Happens when you run the 4-stroke for periods and it doesn't heat up enough.......then the blow-by mixes with the oil and increases the volume.
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