There's your problem.
The high compression that modern sportbike engines have requires a high octane fuel at any appreciable load and rpm. Just meandering around town you might not notice a problem, but at high throttle openings and loads you're going to start detonating. That is a HUGE problem.
Octane rating is the fuel's resistance to knock. An 87 octane fuel cannot be compressed as much as an 89 or 91 octane fuel before it auto-ignites.
Fuel itself can also not be "too rich or too lean." Rich and lean are conditions of the air/fuel ratio, which is not altered by different fuel grades.
2005 ZX-10R Street and Track Whore
Last edited by goingtoscotland; 11-03-2012 at 10:08 AM.