I posted a winterization procedure a couple months ago. This is the new and improved version. I had the service guy at the Mooma dealership walk me thru the procedure when I first bought my boat. These are the notes from that walk thru which I have edited and improved on the last couple of years.

I winterized my boat today and took some pics, so below is the new and improved winterization procedure with pics. Note that I ran the boat on the river for about 15 minutes then winterized her at the boat ramp parking lot so the oil would still be hot.

Hopefully, this will help someone who is considering self-winterizing.

Winterizing Instructions for 2006 Moomba Mobius LSV
(other years and models may vary)

A. Put Sta-Bil in fuel, 1 ounce per 2.5 gallons so 16 ounces for a full tank (40 gallons).
B. Run the boat on a body of water for at least 10-15 minutes to get the engine oil nice and hot. This suspends the bad stuff in the oil and allows it to be sucked out or drained with the oil. It will also allow the oil to drain/be sucked out faster. Drive it back on the trailer and with the engine still running, remove the spark arrester (held in place by a large hose clamp). Spray 4-6 ounces of fogging oil into the throttle body then shut off engine immediately. Replace flame arrester.

C. Let the boat sit 5 - 10 minutes to let the oil cool a little. This would be a good time to disconnect the battery to avoid accidentally causing a spark if your ratchet handle touches the positive cable on the starter while removing the block drain plug. Drain/Change the oil and oil filter (I use a Fram PH30 filter and Shell Rotella T 15W40, crankcase capacity is 5.5 quarts including filter). Use a gallon size ziploc bag around the filter to catch the oil and the oil filter and avoid getting oil on the carpet. I drained the oil at the boat ramp parking lot as it’s a 30 minute drive back to the house and the oil would cool off too much by then. Best method I found is to use a fluid extractor (Pela 6000 worked great for me) and suck it out of the oil drain hose, not the dipstick tube. This way, you know you are sucking it out of the low point of the oil pan since the oil drain hose is attached to the oil pan where the oil pan drain plug would normally be.