Stroker in your case I agree the higher octane will cure the problem. Working the engine hard and getting it hotter than normal will make it want to pre ignite. My BMW is 12:1 and will not run on 87.

I ride an SF and most of the time I am just flying down the road. The new motor only has 400 miles on it before the snow got here.

David Waiting for spring!

 

Ok, I had forgotten the SF is the motard version.