Weedeater 16HP Enduro

I am a new owner of a Weedeater 16 HP Tecumseh enduro . It was my neighbors gave her 50 bucks for it, she had it sitting behind her house. I didn't even look it over before I paid her for it. I think someone was using it for parts. Missing nuts, missing spring in carb, gaskets missing, broken throttle linkage. I had my work cut out for me. Well after a week of hunting down parts I got it running. I realized my sister has the same engine but a 17 hp not a 16 I have a spare engine and parts. Replaced fuel lines, filter, cleaned out fuel tank. Oil in it looked brand new but drained but haven't filled yet. I noticed that mine didn't have a oil filter but the 17 did, I had a cover over where the filter went. So mine has one now with a wix filter. I have done a lot of reading and found that the carbs aren't that great but after I cleaned mine up used tiny wire and carb cleaner seems to run very good. Would like to know what's the best oil use in it. I know it say's 30W, I have read that you can use 5-30. I am a fanatic when it comes to changing the oil in my car almost 300k I use Trop Artic 5-30 can I use that or should I use 30W. Also what can I expect to go wrong with these Enduro's. I have duplicate parts and getting more. Thanks