"ghost--
As i said my boat
"ghost--
As i said my boat is 10yrs old. Merc NOW says it's ok to use synth, but when my engine was built they said it wasn't. I have learned over the years that when it comes to boats, do *exactly* what the book says. Today's 4.3's may be ok with synth, but how do i know mine is? I don't, so instead of risking anything, i take the safe route. And as i said before, i use M1 in *everything* else I own, as I break then engines in with it. I saw no point in switching my boat to m1 with it being 10 years old, and merc sayin not to in my manual. If i bought a new boat, i would immediately put synth in it, but would stay with the merc synth oil.
--chris"