Need some help from guys that know about small engines. I'm changing out a pump on a power washer. Everything was going good until it was time to put the new pump on. The problem is that both the pump and engine shaft have the same style shaft. Both have the recessed shaft hole in one spot and neither one has the "key shaft" to slide into the recessed shaft to turn it. Anyone know if it is easy (or even a how-to) to change out the shaft on the engine to a shaft with a key to fit the pump shaft?