bought a 1984 Panther came with Merc I/O and I am trying to figure out wether it is a 3.0 or a 2.5 litre. The carb has a tag that says 3.0 but apart from that how can I be sure. can you tell from the serial #
I Think you'll find that the 2.5l has Just a Pulley mounted to the snout of the Crankshaft,.....<br /><br />Where as the 3.0l has a Harmonic Balancer, as well as it's Pulley mounted to the snout of the Crankshaft.........<br /><br />Btw,....... Welcome to the forums here at iboats...................
they are very alike and hard to tell apart except for a few small differences....can you post a picture up?? chances are its a 3L if you spotted the tag... the 2.5l is a120hp and the 3L is 135/140 which may be stamped some place...
I wouldn't go by any numbers anywhere. The valve covers swap between 2.5 and 3.0. The casting number on the block is the same on a 2.5 or 3.0. Numbers tell you nothing.<br /><br />The only external way to tell is looking at the front pulley or balancer as was described in the first response..
about the only number I trust on an unknown rig is the tag that is rivited to the block just above the starter. sometimes things get jinky muxed on boats and it gets difficult and expensive to figgure it out.<br /> there is a difference in the shape of the block on the lifter galley side but I cannot recall the details.