Hi,<br />Can anybody tell me the exact name of the recomended sparc plug to an OMC-Cobra 2.3L -87 (4 cyl, ~130hp) Either Champion or NGK, at the moment I have NGK BPR6EFS and the engine is running really bad at high rpm:s and the only thing which was replaced at the service was the sparc plugs (to the wrong ones?)<br />Thanks...