Originally Posted by
Tim Kurcz
Just a few thoughts: 1) The closest I've been able to run piston to head clearance without damage for OMC triples (with lighter/smaller reciprocating assemblies) spinning 8000-8500 is .028" (factory is appx .045"). At .025", engraved markings are embedded in the combustion chamber. 2) Connecting rods are designed for compressive loading. From the looks of it, the rod failed in tension, likely induced from contact with the bearing housings as shown. 3) Free revving such a wicked beast might easily have achieved 10,000+ RPM. Memory from prior Merc 1500 post mortems suggests the rods were only good for 7500-8000. 4) It there's evidence of contact on other pistons/rods, you should crack check all parts at a minimum, and seriously consider a new set of rods.
Tim