99% of the gasoline additives are junk and carburetor cleaner is only good
for killing bugs. They do nothing to remove the varnish, or buildup. Fuel
stabilizer does work, and if you have gasoline and water use anhydrous Ethel
alcohol to remove the water.

Jack

"Doug Kanter" wrote in message
...
My 1996 15 hp Johnson 4-stroke manual says "no gasoline additives". Is the
mfr concerned that some users might not measure correctly for a small fuel
tank, dump in the whole bottle of STP, and screw things up? Or is it
likely
that even a carefully measured amount would cause real harm if used once
or
twice per season?