I've had a lot of gravity-fuel-fed engines where the fuel would seep past the float needle, go through the carb and fill the crankcase if I didn't shut the fuel off even while just sitting in the shop. And, I was pretty good about shutting the fuel off. But on rare occasions, if I forgot to turn it off and I was lucky, it hydro-locked the piston and I knew about it the second I went to fire it off or I checked the oil level and saw it was high. The one unlucky time was when I trashed a $4000 Honda F4 racing engine (it ruined the bearings, cam and crank) because the oil was so diluted with fuel it didn't get enough lubrication. I haven't forgotten to shut the fuel off since.
2007 Suzuki King Quad 450 4x4 - 14" ITP SS112 wheels, 26" Bighorns, Xtreme 3" lift, RT2500 Winch, Twin Air filter, RAM GPS mount, Lowrance GPS, Plano ATV storage box, 2 - Playmate coolers and a RAM self-leveling beer holder
2010 Can Am Outlander 650 Max - 26" Bighorns, 200 watt audio tube by Sooner, BRP rear storage box
2007 Honda Rancher 420 4x4 ES (red), 14" ITP SS112 wheels, 26" Bighorns (Sold)
2007 Honda Rancher 420 4x4 ES (yellow), 14" ITP SS112 wheels, 26" Bighorns (Sold)