Hi Michael, the IDM i run is very similar to the red dot. both engines are picco based and i use the ninja 6 plugs. as for the shims, i tried one removed for 16% recomendation and then refitted it. the top end is a bit better with both shims fitted. yu can gain a bit more bottom end with one shim removed. as for the pipe i used the IDM 2607 pipe, with great results. with gearing, the std ED trans gearing is fine for the engine and pipe combo. if you need a bit more low end then put on a 52t 1st spur. but i generally leave the 46t 2nd spur on all the time.