I know manual says run 89 octane. I have run all 3 grades in mine. It performs much better with 87. I know 87 gives better performance in a low compresson engine. All the metric bikes recommend 87. Why does triumph recommend 89?..... My buddie has a 06 750 shadow with 9.7 compresson as ours is 9.2 and his manual says run 87. One more question, Were are our air/fuel adjustment screws on the 05 Anerica? Thanks in advance for any and all help.
