It has to do with the pick up postioning and the fireing sequence. On the 270 degree engine the ignition system becomes confused by the faster cycling rate. Its the nature of the design. Triumph I guess when designing it never really intended it to go above 8100. So to overcome this problem you have to pretty much design a different system. 2 pickups perhaps? Its not a mechanical problem but an electrical one. Having said all this. There not really much to be gained with this engine by going any higer as you already passed peak hp before this point. Unless you're doing different cams and such. Or perhaps doing a run at the salt flats or such. If you'd like a more detailed explaination of all this drop jojje a line. He's the man who can answer all your questions.
http://www.triumphrat.net/newreply.p...ote=1&p=829142
