Which oil should I use? How much? Xj750

Hello all.

I'm by no means a mechanic. I have a 1982 xj750. I'd like to change the oil. I think last time I remember a salesperson at Auto zone tell me I had to use motorcycle oil since it had special detergents and what not that the motorcycle needed. What do you all recommend and how much oil will I need to buy assuming I'm changing the filter as well? Also my preferred store is WALMART. I'd like to go synthetic if possible. I believe WALMART has castrol and Mobile One synthetics. What weight should I get if in fact I can go synthetic. Also if I do go synthetic how long should I go between oil changes.

Thank you.

 

If you go synthetic, be prepared to dump your oil immediately.
One of my XJ's (starter clutch) can handle syn - the other can't.
Or play it safe and just buy DINO.

I've settled on the "Diesel Spec" oils which have ZDDP in 15-40 weight.
Otherwise you MUST get "Motorcycle" oil, or you will have transmission clutch slipping. It's not the detergents, it's the fuel-economy low-friction additives. . . the oil is TOO slippery.

Drain at 2,000 miles. I save my oil for the lawnmower and other things.
Buy a gallon, but you'll only need about 3 quarts.
Fill (on centerstand) until the oil window has just a little bubble at the top.
That's several ounces above full, to keep the "Low Oil" switch happy and to stay ahead of consumption, drips, and "new oil evaporation".
Check after running when changing oil..Check after a few hundred miles.

 

Check the link in my signature for more information that supplements TtR's excellent advice.