the triples are made of a fairly soft grade aluminum alloy and are very easy to drill out. Almost too easy, I would recommend using a drill stop (of some sort, even duct tape would work)so that you don't suddenly drill thru and have the drill chuck mar or scratch the top of the triple.
if you have to go back to the smaller size riser screws then it is easy to get a bushing to make up the hole size.
05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter
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