<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brad black &raquo;</TD></TR><TR><TD CLASS="quote">we have lots of problems with hi comp bikes pinging on the best premium fuel we have, especially the ram/dp kits that have something like 12.5:1. even 11:1 can be an issue.

you don't need much retard really, but getting the 4 to 6 degrees you need under 5,000 rpm without generating idle issues is impossible.</TD></TR></TABLE>

Brad- Agreed, but if you "soften" the domes of the hc pistons that really seems to help prevent detonation. Knock the edges off everything and make 'em smooth. My carb'd 750/800SS is nearly 13:1 (Pistals) and runs fine on 92 pump gas. The timing plate is retarded 2 degrees. No, I don't daily commute on it but it seems happy enough in town.