Okay, I'm back with some info and a warning. This is a discussion about oil, not grammar or spelling. If we can't have a civil discussion I'll shut it down. That's my prerogative.
There's no reason for auguments. Differences of opinion are expected but not anger over them.
With that said here's where I stand with the Opti-2 experiment.
The high milage engine doesn't like it. I have some theories but that's all. I've tried it three times and did comparisons between my old oil mix which is Stihl 2 cycle oil and the Opti-2. All three attempts resulted in a decrease in power and speed but when I go back to the original mix the engine regains its previous performance level.
Now...the other two motors: Both are Dax 80s, one is very low milage, under 100 and the other is in between the three with just less than 500 miles. Both of these engines display a marked increase in power on the Opti-2 mix. Not just barely noticable but a marked increase. The 500 miler used to top out at about 28mph on the only flat area near my home. It will now do that same stretch at 32 with ease and sounds better than it used to. The power is smoother and more consistant. I do not feel that this engine is suffering from a lack of lubrication but I assume only time will tell. I've put about 165 miles on the motor using the Opti-2 mix and so far it has shown no signs of coming apart, running hot or making any strange noises that you'd expect from oil starvation.
The low milage motor is probably still in the break-in stage even with 100 miles on it because I typically treat my engines easy and don't abuse them. It has been my experience that running them like I do my break-in is a little longer than some. This engine, like it's higher milage brother is also running smoother and stronger on the Opti-2 oil. I was able to discern a difference rather quickly after the first tank and subsequent running has proven to display the increase in power and top end speed.
The high milage engine has a little over 1500 miles on it and runs strong and smooth on Stihl 2 cycle oil mixed 32:1. I have a 48T sprocket on this bike for the hilly neighborhood where I live and it will top out at about 26 mph on the Stihl oil. If I give it Opti-2 my top end is somewhere in the mid teens and I have to pedal up hills that it typically climbs unassisted at 20mph.
Theory: Something to do with the piston rings' inability to seal properly with the Opti-2. Even though the engine feels as if the compression is good there might be something about the Opti that is just too slick, for want of a better term, to allow the rings to seal and under load allows some blow-by. This is just a theory but it is the only one that makes sense to me at this time. To clear up a misconception that I've read here; the Opti-2 is not "thick as molasses" but in fact displays about the same viscosity as any 2 stroke oil that I've used. When mixed as per the instructions at 1.3 ounce per gallon of gasoline the mix is not any thicker than regular 2 stroke mix. It's apparent that the lubricating abilities of the Opti are very good but maybe too good for a high milage engine with some wear on the cylinder walls and rings and will not allow for proper ring seal. Just my theory.
Conclusion: The old motor will get regular 2 cycle oil, probably the Stihl that I've always used and the other two, and probably any future engines will be run on the Opti, obviously depending on what happens as time passes and the miles accrue. I'll report it if there's problems. Oh, by the way, Dax cringed when he rode one of my Opti-2 bikes a couple of days ago. He is not a believer. "Go to 50:1" He said. Sorry, Duane.
Tom
