Used it in all my 5 speeds and use it in my SE 6 speed in my 2002. Never an issue.

 

 

Not wanting to be "That Guy", but personally, I wouldn't run anything in an M8 gear box that I didn't want all over my clutch plates until I verified FOR SURE that it didn't have a case of the "Dreaded Transfer!" I'd stick with Formula+ till you know. Or maybe you already know it doesn't and I should shut up, lol!

 

 

 

I put bel-ray big twin transmission oil in the tranny at the same time I change my primary to Rotella T4 15w-40. The PO ran all Syn 3. Much easier to find neutral now so what you're saying is the Rotella T4 made the difference?

 

Different oils work better in different bikes. I went to Screamin Eagle clutch plates in my 09 Heritage and at the same time switched to spectro heavy primary fluid from Rotella T. I have Spectro 6 speed in my tranny and love it. I could not find neutral at all with Spectro primary oil even after many clutch adjustments. I then changed to Harley-Davidson primary formula plus and it was 80% better but still hung up at times. Before I made these changes I had Rotella T and never had a problem so I picked up Rotella T4 15-40 the other day and put that in and now finding neutral is as easy as ever. Spectro primary works fine in my 06 softail with Spectro 75-90 gear in the tranny. Sometimes you have to experiment.
And I believe the T4 made the difference for your bike. T4 replaced the older T version.