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Oil in 2 stroke engines.

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Is there a way to make an engine that doesn't need a gas oil mix? Could you have an oil reservoir if it was fuel injected?

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Ok yeah makes sense. So not really gonna happen in a dirtbike anytime soon.

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Is there a way to make an engine that doesn't need a gas oil mix? Could you have an oil reservoir if it was fuel injected?

Not in a 2 stroke. Even if you sealed the bottom end you'd have to report the intake to go directly into the piston. In turn you be making it just as complicated as a 4stroke, that would take the fun out of it. And the idea of slapping a "super charger" on it wouldn't work well. Neither would a turbo in the woods... There are YouTube videos of people trying to do that.... Doesn't work well unless wide open all the time.

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Not in a 2 stroke. Even if you sealed the bottom end you'd have to report the intake to go directly into the piston. In turn you be making it just as complicated as a 4stroke, that would take the fun out of it. And the idea of slapping a "super charger" on it wouldn't work well. Neither would a turbo in the woods... There are YouTube videos of people trying to do that.... Doesn't work well unless wide open all the time.

If I'm not mistaken, there were some older bikes in the 70's that used a separate reservoir for 2 stroke oil, just can't seem to remember which bike it was.  I think it was a Yamaha 250 Enduro, I think.  Guess that idea really never took off though huh?  But it sure seemed simple enough.  Gas in the tank, oil in the reservoir, I thought it was a good idea as opposed to mixing gas like we do now.  :devil:

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If I'm not mistaken, there were some older bikes in the 70's that used a separate reservoir for 2 stroke oil, just can't seem to remember which bike it was. I think it was a Yamaha 250 Enduro, I think. Guess that idea really never took off though huh? But it sure seemed simple enough. Gas in the tank, oil in the reservoir, I thought it was a good idea as opposed to mixing gas like we do now. :devil:

Yeah alot of sleds used them but the problem was the pump could fail at any time and you would lose oil to the motor . I don't know much about bikes that used them. I had that issue on my sleds so I stopped using the oil injection and premixed from now on

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Yeah alot of sleds used them but the problem was the pump could fail at any time and you would lose oil to the motor . I don't know much about bikes that used them. I had that issue on my sleds so I stopped using the oil injection and premixed from now on

Gotcha, yeah I can believe that.  If the pump goes out you wouldn't know it until the motor seized huh?  Good point.  I do remember them on bikes.  My uncle had a Yamaha 250 Enduro which I'm sure had a reservoir for the premix oil alone.  I don't blame you.  I'd probably do the same.  But if you're not running oil through the pump, won't the pump seize as well?  I'm just asking because I really don't know. :devil:

Edited by YZ490-DEVIL

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Gotcha, yeah I can believe that. If the pump goes out you wouldn't know it until the motor seized huh? Good point. I do remember them on bikes. My uncle had a Yamaha 250 Enduro which I'm sure had a reservoir for the premix oil alone. I don't blame you. I'd probably do the same. But if you're not running oil through the pump, won't the pump seize as well? I'm just asking because I really don't know. :devil:

Depends . I use to pull the gears out so they couldn't seize in the little pump. And some sleds only had plastic gears so they striped easily
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Not in a 2 stroke. Even if you sealed the bottom end you'd have to report the intake to go directly into the piston. In turn you be making it just as complicated as a 4stroke, that would take the fun out of it. And the idea of slapping a "super charger" on it wouldn't work well. Neither would a turbo in the woods... There are YouTube videos of people trying to do that.... Doesn't work well unless wide open all the time.

Supercharged two stroke works. With a sealed bottom end and an exhaust valve. Check out Detroit diesel for an example. I'm not sure if it's been tried with a gas engine due to complexity and weight since two strokes are used for simplicity and low weight.

Maybe I'll do some googling.

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Not in a 2 stroke. Even if you sealed the bottom end you'd have to report the intake to go directly into the piston. In turn you be making it just as complicated as a 4stroke, that would take the fun out of it. And the idea of slapping a "super charger" on it wouldn't work well. Neither would a turbo in the woods... There are YouTube videos of people trying to do that.... Doesn't work well unless wide open all the time.

Yeah but even so if it was as complicated, it would still have advantages over a 4 stroke. You're still getting lots more power, your engine will last just as ling now, you'll get great mileage, no pollution....Right?

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Yeah but even so if it was as complicated, it would still have advantages over a 4 stroke. You're still getting lots more power, your engine will last just as ling now, you'll get great mileage, no pollution....Right?

Milage would still suck, pollution, likely a bit higher. Everything else seems about right.

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Milage would still suck, pollution, likely a bit higher. Everything else seems about right.

I wouldn't think the mileage/pollutuion would worsen. You wouldn't have that extra gas escaping from the cylinder before the port closed.

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If I'm not mistaken, there were some older bikes in the 70's that used a separate reservoir for 2 stroke oil, just can't seem to remember which bike it was.  I think it was a Yamaha 250 Enduro, I think.  Guess that idea really never took off though huh?  But it sure seemed simple enough.  Gas in the tank, oil in the reservoir, I thought it was a good idea as opposed to mixing gas like we do now.  :devil:

1973 Yam DT 175.  I had one.

 

And the pump STB, so I started premixing.

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I wouldn't think the mileage/pollutuion would worsen. You wouldn't have that extra gas escaping from the cylinder before the port closed.

It comes down to two strokes having lower compression and more power strokes. Two ideal engines, identical besides one being 4 stroke and the other 2 stroke. The 2 stroke will burn twice the fuel and make twice the pollution. It would also make twice the power, but since nothing is ideal, it would likely pollute more and use more fuel for a given power level.

I'd still like to see it happen anyway.

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It comes down to two strokes having lower compression and more power strokes. Two ideal engines, identical besides one being 4 stroke and the other 2 stroke. The 2 stroke will burn twice the fuel and make twice the pollution. It would also make twice the power, but since nothing is ideal, it would likely pollute more and use more fuel for a given power level.

I'd still like to see it happen anyway.

Ok, yes. But still would it not waste as much gas for being a 2 stroke? Oh and also the oil would not be burning in the gas so less pollution there.

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1973 Yam DT 175.  I had one.

 

And the pump STB, so I started premixing.

Crap, you're right, it was a 175, not a 250.  Damn my memory is going.  Thanks for reminding me.  I have some a few gems of memories in my head, but as time passes, they seem to distort a bit. :devil:

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Lots of bikes have had oil injection over the years, and lots of snowmobiles and outboard boat motors still do.

The popular opinion about oil injection being failure prone is greatly overblown in most cases.

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Lots of bikes have had oil injection over the years, and lots of snowmobiles and outboard boat motors still do.

The popular opinion about oil injection being failure prone is greatly overblown in most cases.

I had an oil pump for the injection go in a sled. I was climbing a hill and it high revs and motor locked got home and looked. Oil pump died. Ever since then I premix. I take the extra 2 mins to do it. So much less worries

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Crap, you're right, it was a 175, not a 250.  Damn my memory is going.  Thanks for reminding me.  I have some a few gems of memories in my head, but as time passes, they seem to distort a bit. :devil:

:lol:

 

I know exactly what you mean.

 

I have one pic of that bike.  I couldn't remember what year it was so had to use the Googler.

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