Thinking of leaving my DL650 -09 under covered by a tarp in an unheated garage during the winter. The temperature here may go down to -20 ° C (-4 ° F) but mostly it is at a few degrees of minus C.

Should I consider protecting it in any particular way (risk of coolant freeze?)?

Writer, check the coolant. It must be good for colder temperatures than expected. Fill tank with fresh fuel ,non ethanol, if possible, with the correct amount of fuel stabilizer added. Go for a good long ride. At end of ride top up tank, not overfilled. Drain and change the oil and filter.Lube the chain.Inflate tires a couple of pounds higher than normal riding pressure. Remove the battery and store it in a warm place where it can be on a battery tend er if available or placed on a 2 ampcharge for a hour every 2-3 months. Place bike on centre stand or side stand. Centre stand reduces amount of space needed.Cover with a breathable dust cover. Uncovered is better than a non breathable cover. Cheers Doug

Great advice so far. I would add that if small animals could get in, it's worth taking the time to tape over the air intake.

Forgo the tarp unless its a breathable motorcycle cover.

Also a good idea to check the glycol content of the antifreeze to verify it at the proper percentage to offer protection for the temps it will see.

Top up the tank is a good idea. Changing the oil is up to you. If the oil is close to needed changed because of mileage go for it. If your only around 1/2 way through its life cycle I'd not change it. The additives package in the oil is still effective and will naturalize acids leftover from combustion.

The other myth is your tires will flat spot if you don't get the weight off the bike, over inflate the tires and/or move the bike every couple of days. Trust me over the winter even inflated with 3psi they won't flat spot.

So many people think unless you are overmaintaing a motorcycle you are undermaintaing a motorcycle. A motorcycle sitting out of the weather for 3, 6, 9, 12 months is not long term and really doesn't need any special treatment. I've brought several 40+ year old motorcycle that sat for 10, 15 or 20 years back to running order with a lot less work than you think. Change the oil, clean the carbs and gas tank put in a fresh battery and hit the starter.

they can also get under your seat etc. I use mouse traps.

I would forgo the tarp as well. I would not start the bike unless you are going to ride it. Battery tender or remove battery and keep inside. If you could ride it once a month that will be even better than storing it. Gas stabilizer.

kfh000

Make sure the gas tank is full. Maybe add stabilizer. Wouldn't hurt to change the oil before parking it.
Leave the battery in the same cold environment (it will self-discharge more slowly), but only if you can ensure that it stays charged. A fully charged battery will not freeze at any temperature it's likely to see.

Thank you all!

I have winterstored another bike in the same garage since -96. With removed battery, filled tank, engine and other metal parts sprayed with 5:56 and under tarp. With absolutely no problem!
But the situation with a "water" based cooling system is new to me so I will certainly check the level of anti freeze.

Earlier years I have stored a bike in a heated storage room. But the door opening is about 80 centimeters above ground level so I have had to use a home built ramp and drive up and in. Was nervous every year because I only had about 10 mm free space on every side of the handlebars. With the DL650 there will only be about 5 mm and I rather not risk that :-)!#

You can buy cheap and simple testers at autopart stores that allow you to determine the freezing point of your current antifreeze coolant in a matter of minutes. Alternatively, take a sample to a car or motorcycle dealership: They should be able to determine the freezing point for you relatively quickly and cheaply. If only for peace of mind.

If you're afraid of moisture building up under the tarp, place a small (let's say 15W or so) lightbulb under the tarp as well. Or use another heat source that produces about 15W. If you manage to heat the air under the tarp at least about 3 degrees C over ambient, it's going to be virtually impossible for moisture to condense there.

All good advice, except for where to store the battery. It's a common misconception that a warm place is best for a battery. A cold environment (but not freezing) is best for storing a battery. A cool battery will discharge at a slower rate than a warm battery. Warm is best for cranking power, but for storage, keep it cold.