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You may possibly get quite a few opinions in answer to your question.
But first, has the primary been separated from the original oiling system that uses engine oil to lube the primary?
If it has been separated, I used Type F ATF.
Stand the bike up and block it in place or have someone hold it up.
Through the derby cover fill with the ATF until the clutch shell is in the oil.
That way the shell will pick up the oil and throw it around in there keeping things nicely lubed and clean.
I would not fill it to where the clutch plates are touching the oil, just the clutch shell.
If you start with a new bottle of oil, you can then see how much you put in and know how much to put in next time without having to stand the bike up.
BEL-RAY PRIMARY OIL -- ATF works and works good -- i used the bel-ray in my wifes sporty -- i use the bel-ray 4 speed tranny oil in all my bikes that require it-- i like it for 1 reason other than the additives its red and you can tell if the oil leak is engine or tranny --
First off is it a sealed primary or is it still stock with all the hoses hooked up ? Stock you don't do anything it lubes from the oil pump and is pulled back into the system .
If you only have 3 oil lines on the bike use ATF or pri. oil and fill it just to the bottom of the clutch pack about 3/4 to a cup or so .
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