guy said he was out on the lake and lost power.you also say the number 2 cyl is low on compression.you my friend have a burnt piston.what happens is the outside crank seals fail and the cyl sucks in too much air causing a lean condition.pull the head and look around the outside of the piston,beings it does still have some compression on that cyl.you can more then likely save the cyl without reboring,but the engine will have to come out.to replace all 3 crank seals. the crank has to be separated,this is a job for a shop with a jig to put it back together correctly.the center seal is a double seal and you could probably skip replacing that one,this would save you alot of time and money as you could probably replace the outer seals without pulling the bottom end apart.you gave 100 for it,you will have probably another 3-400 in it if you do all 3 cranks seals.so you still won't be doing to bad on the deal and you'll have one you know is good.for the price of pistons,i'd throw in a set of wiseco's.way better then the factory pistons and maybe 5-10 bucks more.