Brother recently took his boat equipped with 2002 Evinrude FICHT 70hp out for the first time this season. Engine started and ran fine. Upon starting for the return trim back to the launch site, the engine revved very high at idle. A visual check didn't reveal anything obvious and a subsequent restart resulted in the same result: extremely high idle rpm; however, this time was accompanied by an explosion which blew the cowling off the engine.and resulted in a fire in the engine area. Has anyone experienced anything like this with this usually very reliable engine or have any ideas as to what may have caused it. The engine has not bee repaired so any suggestions as to where to look will be appreciated.
