[pelican]

"piston" ? "rings" ?

pull the cylinder heads off-see what everything looks like inside the cylinders - if the tops are blown or melted off the pistons,it's a result of detonation...it usually effects the top cylinders-heat rises...problem comes in if the crank is damaged...usually,what happens is a cylinder detonated-and "shrapnel" is shot around-blocks are damaged,rods are damaged,and cranks are damaged...
either way,the engine's gotta come apart,to really make a diagnosis-either way,you're looking at either a full powerhead overhaul,or,a new powerhead...my opinion-$200,no deal...you're buying a cat in a bag,yep,you can see if the lower unit shifts,and the hydraulics-tilt and trim work-but,that it...it's all a guess...what caused the failure ? engines don't fail on their own,something causes the failure...personally,i would pass on that deal...a 14yr old blown engine,is no deal @ $200...