Mixing Two-Stroke Premix 100:1 Into Gas???

4 replies to this topic
  • i_wheelie_longer

Posted June 26, 2010 - 05:41 PM


Anyone add a tiny bit of two stroke synthetic premix oil into their gas for their 4 strokes? A couple people I know add premix 100:1. Is there any negative effects of this? Or is it more beneficial with a little extra lubrication for the piston, cylinder, valves, and valve seats? The bikes don't smoke or anything, and be mindful I'm not saying to mix oil like you would on a two smoker.... just approximately 100:1. Any thoughts?

  • zukboy789

Posted June 26, 2010 - 05:45 PM


I wouldnt because there is a reason it takes straight gasoline. ANd second, you may get deposits on your valves, etc....

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  • grayracer513

Posted June 26, 2010 - 07:01 PM


This tactic is an old one, dating to before the second world war. It's called "top oil". It has some benefit when using a "dry" fuel, such as some racing fuels or alcohol, since the compression rings are lubricated only by fuel in a well built engine.

But it's not as important as it once was, and isn't required at all with most pump fuels unless you run E85 (shame on you). 100:1 is too much, anyway. 200:1 is more like it.

  • davek18

Posted June 26, 2010 - 07:57 PM


The oil mixture in the fuel actually reduces the octane rating a smidge too, I have used premix in my 4 stroke in a pinch with no noticable effects, but I see no reason to intentionally do it. Oil fuel mix has a shorter shelf life too, burn it all up if you use it, don't let it sit for weeks in the tank.

  • SAthump

Posted June 29, 2010 - 11:04 AM


I run redline fuel system cleaner in my gas. It lubricates, cleans and helps prevent knock. Been using it for about 13 yrs works great.

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