Snapper RP217018BVE Walk Behind Mower

I have this older Snapper that still starts on the first pull.

I need to replace the drive belt. I also need to change the oil and air filter.
Where should I go to find the parts?

A manual I found online didn't tell me the kind of oil I should use. IIRC (not a sure thing at 83) I used 30W Pennzoil in this mower. Is that a good choice? If not, what should I use?

Yes, straight 30w oil should be fine. I googled your model number and found lots of places selling parts for it. Your belt is snapper part #701354YP. You’ll need to look for an air filter by searching with the engine model. I expect it is a 7HP Briggs but not sure. If it’s the Briggs, the air filter is probably part#491588S. Search on that and see if the picture matches your old filter. I buy most parts online and use Amazon because my wife has a Prime account so shipping is usually free. If you have to pay for shipping you may do just as well shopping at a local store.

Thanks for the info Oddjob. I found a different part number on ereplacementparts.com. It says the belt is part# 7046784YP, 3/8"x24". I found the #701354YP but didn't get dimensions.

I have a couple quarts of 30W Pennzoil. I looked online at WalMart and they posted it for over $12 a quart!!!!. Yowzers! It's been a long time since I bought a quart of oil. I used to buy a case of the stuff for that price.