I went to LHS today to get fuel of high nitro and castor oil since
my Norvel .061 engine needs it, but they didn't have one in stock
and the shop owner said "the story small engines require caster
oil is out-of-date, now high percentage synthetic oil can take place
of caster oil".
I could have ordered castor fuel if I wanted, but I bought one of
26% synthetic oil / 30% nitro.
I like synthetic oil because it is more dry than castor after run.
I will use it for my Norvel .061, but has anybody ever used sunthetic
oi fuel for any mini engine? Thanks for your info.

Tsutomu Mabuchi