Stormin, 2-stroke oil is the worst thing you can put in a crankcase,
its designed as a combustion product and will cause him to consume more
oil as its viscosity is less then crankcase oil. It also has totaly
different ratings and parameters for protection. Which could ruin his
He should try a tune up . A compression test without and with adding
oil to the cilinder , to determine if its valves or rings, and how low
it truely is. Thicker oil, one designed to expand valve seals. And a
hotter spark plug. ,may cure the problem. What grade oil and heat
range of plug only experimentation will decide.
Actualy OP said smoke on startup. That indicates valve guides , and in
itself is not a bad thing, as it gives instant lubricaton on startup ,
when it is needed most. Some new oils are advertised to swell seals.
Another person recomended the breather, another interesting idea to be
2 stroke in a crankcase, well when I was 10 yrs old I did something
dumb , put vegetable oil in the mower.