I have red many different things. But, i still have a few questions. I know the breakin oil to fuel mixture is 24:1 for the first two gallons then 32:1 after. But what type of gas do you use? i heard 87 octane. And also does it matter if there is ethanol in the gas?
Questions about proper break in for Skyhawk GT5
- Thread starter croy2007
- Start date
As far as the oil, any good synthetic 2 cycle oil seems to work out best. I myself use Amsoil. AMSOIL - INTERCEPTOR? Synthetic 2-Cycle Oil (AIT)
I burn 87 octane, non ethanol if I can find it, there is one station within 30 miles so mostly I burn ethanol fuel. Have no adverse effects. Been running my first build since 3/2009
The GT5 is a high-compression engine, therefore, you need to run a higher octane. I have a GT5 and broke it in at 24:1 w/ 87 octane. Now well after break in I have about 4000 miles on my motor, and I run 40:1 semi-synthetic w/ 91 octane. A very nice combo if you ask me! 
I'm gonna attempt to run Opti-2 in the near future
I'm gonna attempt to run Opti-2 in the near future
I know that higher octane gas isn't needed in these little engines, but mine seem to run a little better when I use 91.
The lower the octane the lower the burn, that number drops more when oil is added, causing knocks or 4-stroking. Higher octane fuels have a higher concentration of heptane, which helps compensate for the added oil and helps reduce 4-stroking. I know my bike does not like 87 octane at all.
Lower octane burns faster, higher octane burns slower. That's the only difference in in gas octane. Google it.
If adding oil to the fuel lowers octane rating the fuel will burn faster.
High compression and high timing advanced performance engines need the fuel to burn slower to reduce spark knocking.
Lower compression and timed engines need the fuel to burn faster so that it has burned up before the exhaust cycle.
Using high octane in a ln engine designed for low octane actualy causes a decrease in horsepower. The fuel is still burning during exhaust and much energy is lost instead of being harnesed by the engine. Well documented in many different dyno tests with many different engines. Google it.
If adding oil to the fuel lowers octane rating the fuel will burn faster.
High compression and high timing advanced performance engines need the fuel to burn slower to reduce spark knocking.
Lower compression and timed engines need the fuel to burn faster so that it has burned up before the exhaust cycle.
Using high octane in a ln engine designed for low octane actualy causes a decrease in horsepower. The fuel is still burning during exhaust and much energy is lost instead of being harnesed by the engine. Well documented in many different dyno tests with many different engines. Google it.
