oil capacity '82 KZ550 H1

any help would be great

del

3 litres.

what grade of oil would be good

The subject of "oil" is one of the foundations of this site I think:)
You Americans have widely differing climates whereas here in England its much the same allover so really I suppose it depends on where you live/your local climate.-To take it to extremes, Alaska compared to California compared to Colorada would/could require different oils.
There seems to be an agreement that generally, something like 15/40 diesal engine oil is a safe bet.
Shell used to do one which has been mentioned on here in recent past.
Whatever you decide,please don't be seduced by the "motorcycle specific oil" that your friendly dealer will put you into hock for buying.Even though its good oil, it can cost silly money,esp bearing in mind that you will be changing it on a regular basis. I go 2000-2500 miles between changes.
Ridden like an old man with brief periods of gay abandon:silly:

I'm in texas, so it's hot most of the year. winters usually don't get too old. so 15w40 would be good?
yeah don't worry I know not to waste money on "cycle" specific oil, guess I'll be back at a store before the day is over

3 quarts of 20/50 for warmer climates. I use 20/50 here in Northern CA, becuase I ride harder, and I change the oil and filter regularily. Yes, Motorcycle-Specific only, but we're not going to bring that topic up again, right?