Ok thanks is synthetic ok to use or just stick to regular?
Its not that significant a difference.
Really if you want to use something I have a little more faith in I would shop around for some Rotella T from Shell.
The 15/40 is turbo diesel rated.
That means its good for high bearing loads, keeping engines clean and heat.
Three things these engines are bad for.
Hard on rods and rod journals ( bearing load ) dirt no oil filter ( high detergent package ) and of course heat because they are air cooled ( turbo rating ).
Now since we are on the subject of oil and lubricants.
I would recomend to enyone the use a top lube on these engines.
A low ash oil 2 stroke or aviation mixed ver thin into the gasoline 150 or 200 to one will only help keep the top of the liner slick.
Also check your timing and run up to 25 on these engines ( no more though )
Some clones are coming with timing as lazy as 18
This is to improve the emissions running late timing.
But what it does is make a dry liner situation worse.
AS the RPM goes up the late firing starts to burn the oil of the liner causing more heat and wear than needed.
And richen up the carb a touch too!
More timing and richer mixture add some top lube as I sugested and regular oil changes.
I think that about covers it.
These engines can last much longer than they are advertised if they get care.
They are generaly rated for as little as 200 hours of service life ( did you know that ? )
But if you care for them they can go 2 or 3 times longer