My motorcycle was completely out of coolant, should i be concerned?

I recently bought a 2004 Honda VTX 1300. It only had 5000 miles on it, and i've put about another 500 on it in the last few months. I never checked the coolant level until today, and I noticed that the coolant reservoir looks completely empty. I haven't had any problems with the bike, it starts right up and runs great. And the temperature light has never turned on. The only thing i've noticed was today after i let the bike idle for about 15 minutes, i turned the engine off and heard a weird sort of whining sound, which stopped when i turned the power off. Anyways, i'm going to buy some coolant tomorrow, but i was wondering if i should be concerned at all that there reservoir was completely empty?

Added (1). I do plan on finding out if there's a coolant leak, and where. I guess my main question is whether it is possible that there's already permanent damage to the motor, even though it seems to run perfectly, and the temperature warning light has never lit up?

The cooling system is probably leaking. Service the the system and check for leaks when the engine is running. Should you be concerned? YES.

If still running fine you're probably OK. BUT find & fix that leak As soon as possible.
Either take it to a decent mechanic or buy a copy of the manual for that model & read the section on the cooling system. Many modern vehicles need t ohave air bled out of the cooling system after a drop in level.

I don't think you should be concerned. It's mid-December, not the time to be concerned about coolant, but it wouldn't hurt to add it now. When it is needed, come Spring, it will be there.

Are you sure the temperature warning light bulb is working?

Of course you would be concerned. Honda engineers did not specify a coolant system just to add weight to the bike.

You might have been lucky but you should still be concerned.

Your VTX has cooling fins on the cylinders plus this is winter time. Very likely no damage was done to the engine due to operating during the cooler weather.

As pointed out, locate the leak. Most likely the tubing to the overflow canister is loose or the hose clamps from the radiator need to be tightened. The VTX 1300 engine is pretty bullet proof and can take a lot of abuse before failing, and you haven't abused it. Recommend using the Hondaline coolant.

As an unrelated suggestion, change out the steering head bearings for those of the VTX 1800. The 1300 bearings are prone to failure sooner rather than later. The VTX is a discontinued model and has been discontinued for several years so you need to keep up on the maintenance. The engine is still used, however, on the Fury and related models.

Overflow tank empty-- but did you check radiator? Actually take off cap and look inside- might need a mirror. If you were 'completely out of coolant' engine would let you know. Out of' overflow bottle ' means no reserve but seems like radiator still working. One minor leak problem on cars and motorcycle is the hose from radiator cap/neck to the overflow bottles- hose leaks, hose clamps weak and dripping. Sometimes crack in overflow bottle. Check those areas first, get proper coolant from Honda dealer- a lot of automotive coolants have silica antifouling additive and that is not good for the motorcycle water pumps with 'open' bearing, honda Motorcycle coolant is made for the motorcycle system, doesn't have the silica-think extra fine ground sand- but uses some gell coat additive similar ot what some Diesel coolant additives use.

Yes

Check the radiator and if full, fill the coolant reservoir. Make sure the hoses are connected. My VT 750 had a hose yanked out by a limb in the rode, the tank went dry.