Hi Guys,

I have read a lot of posts that says during running-in don`t 4-cycle 2- Stroke ABC/ ABN Engines.
Well this is not true. I ve 36 OS engines all broken-in in the 4-stroke regimes and all running well. I never had any cylinder peeling either.

I also wrote a letter to OS engines Japan back in 2001 asking about this and they confirmed that peeling of liner is not because of running in 4-cycle regime but due to lack of lubrication caused by synthetic fuel and running engines in dusty environments e.g (areas where sea sand blows as most cases were reported in US)

I use a fuel which is a blend of 20 % pure Caster Oil and 80 % methnol since here in Pakistan Caster Oil is very cheap and hi-quality.When it comes to lubrication nothing does it like caster Oil , its onlt downside is vanish residue.

The Lubrication mechanics inside an engines are Hydrodynamic lubrication and boundary layer lubrication.The shear characteristics of Caster Oil are superb as evident from the Bingham diagram and this is the area where it beats synthetic oils. Since in America most of commercial fuels available are either synthtic or blend with caster they dont offer superior protection at low temperature this is point where break-in is done and peel off may occur.

So the major cause of peeling or engine seizure is not 4-stroke running of 2-stroke engine but it is function of the fuel used.

Just to give you an example of how fine my engines are still running by using this break-in method I am quoting My 61 SF ABC. I log my flights and I ve done 150 flights with this one and it is still running as good as new, turning a MA Race tip 12 x 6 @ 12700 , 80 Methnol / 20 Caster Fuel, Ambient Temperature 15 Celcius, Plug OS # 8 , Elevation 700 '

Khizer