Engine rebuilding is not something that just anybody can or should do. Rebuilding outboards takes experience and the correct tooling. The rebuild process isn’t as easy as pulling it apart and replacing the piston with a new standard size or even a new standard set. Take this post into consideration we found online for sale. The poor guy had his engine ”rebuilt” and still has problems with it. Youtube mechanics are not reliable enough to put that kind of money into. Save yourself some time and money and leave it up to the professionals.