My toro commercial with a Kawasaki FJ180AV 6.5 hp motor smokes at startup, occasionally? My nephew normally runs it while I trim and he told me after about the 4th dump it smokes so bad you can barely see the mower it does stop after awhile though. he loves this mower. It totally kicks the **** out of my HRX. Any ideas. I use 10W-30 Valvoline. Outside temp doesn't seem to matter anywhere between 50-80 deg. I know very little about this machine. We picked it up on the street corner during spring cleanup week!!!! So I have a little wiggle room as far as repairs. I am a fairly decent small engine mechanic so feel free to fire away. Will trade advice on Bobcat mini-excavators.