You can buy Amsoil here: Amsoil or locate a dealer near you, or become a dealer or preferred customer yourself. If you've got buildup with a synthetic, you're burning way to much oil. There is NO - I repeat NO- dino sludge oil made that is even close to the synthetics. Of course they work, they worked for decades. Synthetic just works BETTER.

 

you can only say it burn clean if you remove the head and check the inside cylinder walls and pistons wash,the port cylinders too,then you'll
see some MAJOR build-up at the exhaust port,i've tried ALL klotz oil
and amsoil stuff at 50-1 ratio and always run too damn pig...
simply that engine is not a high revving motor with no power valve,
so it only need standard oil...