Quote:

Query:When you change 865cc stock cams over to a set of 790cc bump sticks, apart from the intake upgrades, are there timing, ignition changes that need to be made as well in order realize the performance gains? If you know, then by all means, chime in...thanks



A bit late on this one.

When any 865 has it's cams changed for 790's or other performance cams the ignition timing should also be changed.

There is a massive difference between ignition advance on the OEM 865 and 790 bikes. This is due to differences in cam duration amognst other things, with the 865 cams you have a much higher dynamic compression ratio which helps the fuel burn quicker and requires less ignition advance. If you just change your cams without adjusting your ignition timing, you're not getting all the potential power that your new cams can release.

Mike (UK) _____________ 2008 Bonnie Black Special 2010 Speedmaster https://www.triumphtwinpower.com