cb450sc Piston and Rings

[chopin2323]

So, I have a 82 Nighthawk cb450sc engine with compression in the 130's on both cylinders; it should be in the 180's. I have replaced rings before on other engines, but now I am thinking of boring out the cylinders ont his one up one(0.25). Should I even be thinking this or should I take it to a machinest and get their opinion? If I do need to buy some oversized rings and pistons where in the world should I buy these?

 

[PLAZACYCLEJOSH]

The pistons have been discontinued through the factory, which can make them hard to come by, Ebay would be a good bet on this one