What's the practical upper operational limit to how much 2-stroke oil
can be added to the fuel and still have reliable operation? Options I
can think of:

- Eventually you'll have so much oil it fouls the plugs (unlikely?).
- Eventually you'll have so much oil it lowers the effective octane
rating of the fuel (unlikely?) to the point of detonation/preignition.
- Eventually you'll have so much oil it lowers the power output such
that it won't make takeoff power.
- You can't have too much 2-stroke oil - it'll run on 1:1.

Is the upper limit so far above how much you'll ever accidentally put in
the tank so as to not be a factor? I am envisioning accidentally adding
the 2-stroke oil twice - doubling the mix ratio. Probably not a concern
- just curious.

Side question: How long will it run if you forget to put any into a load
of fuel? Would there be any way to detect this condition? Will your
fuel calibration be off enough to detect it (assuming capacitive sensors).

Regards,

Matt-

Jim Mederer reports up to four ounces per gallon does not hurt.
George Graham flew from Tennessee to upstate NY forgetting to put oil
in the fuel. Engine continued to run for dozens of hours. Engine never
failed up until he died from cancer this year.
-- Paul Lamar ...No rotor no motor.

Matt,
In the earlier days of 2 strokes is wasn't at all unusual to see a 20:1
mix! This was with a fairly easily burned bean oil. With synthetics the
ratio went up usually to 50:1. (8 ozs/gal) This is when the oil is the
only lube source in the engine. Most rotary flyers mix 100:1 to
150:1. So unless you are severely lacking of short term memory you would
have a hard time putting too much oil in. The biggest problem you would
have if you did, and got the engine to start is that the oil burns
hotter. More BTUs/gallon than gas. in a high output WOT situation the
engine would run very hot. This isn't as big a worry with a rotary as
with a piston engine. The 2 cycles would hole a piston quickly when
runnig a oil-rich mixture. But remember that would be around 20:1. You
would have to leave a few gallons open in your tanks and then fill the
remainder with oil to get that!
Bill Jepson



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