you should get a new crank, if you weld and regrind honda cranks they don't last very long. And remeber that honda berrings are color coded and each color bering has a diff tolerance. When you rebuild the engine with a new crankshaft, do a Complete teardown and wash every part in a parts washer. Since you have rod knock, there are pieces of metal in every knook and cranny of the engine and moving parts. If you don't have the ability, tools or time to do this, go buy an engine from attarco or a place that sells motors. Oh and get a plasti-guage they're like 2bucks