Seems like you got a good deal for C$230 for a 621 with some light rust.
If the engine sounds loud, check the muffler for internal rust. The baffles may have rusted away. You may need to buy a new muffler or find a used part. I'm not sure how comfortable taking things apart, but refer to this parts diagram to make it easier. Take pictures as you go along so you can review them when you you put things back together.
http://www.boats.net/parts/search/Honda/Snow%20Blower/0/HS621%20A-A%20SNOW%20BLOWER%2C%20JPN%2C%20VIN%23%20SZAN-1000001%20TO%20SZAN-1038238/FRONT%20COVER/parts.html
I would start with checking the auger drive belt for tension. Take off the belt cover on the left side with a 10mm socket. Adjust the belt tension if it seems loose. You want to adjust so the belt doesn't slip on the pulley, but not too tight. If its stretched and you run out of adjustments, replace with a new belt. There is a metal plate with a whole bunch of holes on it. Place your bail cable and the tension spring closer together to get more tension. Be careful and wear gloves to protect your hands while working on this part. Also, wear eye protection, those springs can fly and will hurt.
The next item to check is the rubber auger and paddle blades. If it looks worn and leave large gap between the rubber and the housing, or frayed, replace them with OEM parts. You can get aftermarket ones for 1/3 or 1/2 price of OEM, but it may not lasts as long.
Next, check the plastic scraper bar. There should be some material to cover the metal bar and should be the same thickness across the front. Replace if it looks thin or you see any metal from the bucket showing. You should always replace the scraper bar when you get new rubber paddles. Otherwise, you will wear out your new rubber real fast.
Next move on the chute. The left and right movement should be consistent and snaps into detents, no sticking at either extreme. It it is, then there something between the collar and base. You can take the chute off and clean the interface. Put a thin layer of grease to make it rotate smoothly. Don't use too much because the grease will attract sand and turn into "sandpaper"
Next check the chute deflector. It should move up and down consistently, again no sticking. There should be some drag friction on it as you move up and down. There should be plastic washers on the slot that provides friction. Check that these washer have at least 1/16" thickness. If they are too thin, replace them. Tighten the bolts to get a enough friction to hold the chute deflector in position when the snow hits it , but not too much that it's difficult for the operator to move. Tighten the nut in small increment equally on both sides until it feels "right". Make sure the nut is a Nyloc type so it doesn't vibrate off.
Next is to warm up the engine and drain the oil. Tip back and let the snowblower rest on the rear bar. It will stay in that position to help the oil drain out of the engine. Put in 5W-30 oil or synthetic if you wish.
I would go over all the fasteners on the handles and plastic covers to make sure they are all there and tightened. If it's loose, it will spin it self off and fall on the snow the next time you go out.
This message was modified Nov 24, 2010 by aa335