I am not 100% on this but there where modifications done at 09 previous models had numerous problems.. Ign coils, plug heat range and Iridium plugs were recommended..
I was just considering maybe your 09 madel has all or some of the earlier parts fitted, the reason I mention this is because my 05 had a engine upgrade kit fitted and the Ignition coils and plugs where part of the upgrade making it equal to the 09 mods made by Triumph..
other than this AFR rich running and plug fouling is one of many other issue that could be causing a misfire..
Sorry cant pinpoint for you..maybe someone else can elaborate..
