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how long will premix burning engines last?

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today i was ridng with some of my freinds, and the only smell in the air was that of 2 stroke oil on a summer day and oh waht a smell that is.

but i began thinking, and being a noob...

when it finally does happen, and direct injections are put into two strokes,...... will they still burn premix?

i know that they will cycle only air through the crankcase, but how will it be lubricated if there is no sump lubircation their either?:smirk:

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There are some 2 strokes with oil injection... you never know what they may do in the future.

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So do the evinrude engines that Are direct inject two strokes have oil injection? So they still burn oil

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You guys act like there never has been injected 2 strokes before... YES they will have pre-mix...maybe even a small oil tank like the 70 street bikes had

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I get this feeling that we will be mixing gas for a LONG time to come. Even if the bike is oil injected, then some people will still opt to premix their gas.

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I get this feeling that we will be mixing gas for a LONG time to come. Even if the bike is oil injected, then some people will still opt to premix their gas.

As proven by all of the people currently putting premix in their four strokes.

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but if the gas is injected after all the ports close, what lubes the crank?

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but if the gas is injected after all the ports close, what lubes the crank?

My guess is that the oil is injected separately into the intake tract, or directly into the crank bearings or cylinder.

Separate oil tank + separate gas tank = winning

Disclaimer: I know nothing of direct injected two-strokes, other than reading on this board that they're used on boats or something. Never even seen one.

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today i was ridng with some of my freinds, and the only smell in the air was that of 2 stroke oil on a summer day and oh waht a smell that is.

but i began thinking, and being a noob...

when it finally does happen, and direct injections are put into two strokes,...... will they still burn premix?

i know that they will cycle only air through the crankcase, but how will it be lubricated if there is no sump lubircation their either?:smirk:

I hope they dont ban 2 strokes or I am sol!, that sweet smell in the air also chases the misquitoes away, up here in the north woods

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There are some 2 strokes with oil injection... you never know what they may do in the future.

My 1972 suzuki 2 stroke 250 had oil injection. you filled the reservoir under the seat. You put regular gas in it, the stuff got mixed somwehow - worked great - thatwas my daily driver for 2 years, and dirt bike to boot!

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Most DI two-strokes (perhaps all?) use oil-injection. Some inject the oil into the crank somewhere, others feed it directly to the main bearings, and any oil that runs out the sides of the bearings lubricates the wrist pin and cylinders.

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The injected rotax sled motors use a sealed cavity around the crank end bearings packed with isoflex grease. Been doing it since 1999-2000 and it's proved reliable. The cente crank bearings (twin cyl) are sealed on one side and lubed from a bath of oil that also lubes the water pump and oil pump drive shaft. Because your not trying to slobber lube to the far ends of the crank the injected oil can be reduced to levels lower than premix motor would allow. Rod ends and rings are still oiled conventionally but are built bigger and/or with more needle bearings with a cageless design. Electronic control of the oil pump can do things like completely turn the oil off at idle, or turn it up whn conditions dictate. They use VERY little oil when running, why they can than meet 2012 emissions despite still burning a little. There's a little bit going on with the oil they specify too, but that another topic.

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What have you heard or known them to premix with?

just 2 stroke oil, i have heard of people mixing 100:1 in 4 strokes, it supposedly gives the same effect leaded fuel used to have

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just 2 stroke oil, i have heard of people mixing 100:1 in 4 strokes, it supposedly gives the same effect leaded fuel used to have

Does this mean what I think it does? I have heard that guys were doing it to extend valve life; but, there was no evidence as far as I know that it actually did or does. I even read that it destroys the basic principles of what the new F1 motors were designed to do. When you have a stroke that is shorter than your bore width, the odds are already stacked against whether or not you can fool the bike into believing it is a lead based fuel simply by adding 2 stroke oil :smirk:.

On a further note, I consider it a modification for the sole reason that if our fuel was meant to be premixed on our four strokes with F1 technology, it would come highly recommended by the manufactures and manual.

Edited by nokickstandsallowed
Added thought.

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Does this mean what I think it does? I have heard that guys were doing it to extend valve life; but, there was no evidence as far as I know that it actually did or does. I even read that it destroys the basic principles of what the new F1 motors were designed to do. When you have a stroke that is shorter than your bore width, the odds are already stacked against whether or not you can fool the bike into believing it is a lead based fuel simply by adding 2 stroke oil :smirk:.

On a further note, I consider it a modification for the sole reason that if our fuel was meant to be premixed on our four strokes with F1 technology, it would come highly recommended by the manufactures and manual.

i dont do it but can see why people would, it is supposed to cushion the valves, and even if it doesnt, i doubt it can do any harm

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