to reduce friction between the parts of a car
You should drain the oil in the engine. Put engine oil back in the engine because the transmission oil is not made for engines and will hurt the moving parts of the engine if left in.
If you have the owners manual to the vehicle, it will tell you exactly what to put. Also if you open the hood to the engine compartment, you should find the recommended oil type on the motor where you put oil or it should be stamped somewhere in the engine compartment.
With a 4.6 L engine, should be 4.5 L of oil.
SAE 10w30 is a good choice.
30 weight
It depends on what you SHOULD have put in and what you DID put in and the age of the engine. Most of the time it won't make much difference.
it will hold about a half quart of oil
Crankcase oil is engine oil , so yes
5w-20
10w30
If you put it in the gas just empty the tank and put new fuel in it. If you put it in the oil reservoir drain oil and put new 4 cyc. oil in let warm up then change it again it should be OK.
How much engine oil do you put in a ktm 85