Hi Bent Trigger, yes there is a lot of internal dirt shown in your photos. There is a product called flushing oil which will remove most of it without a complete disassembly. Get the unit running and then drain out the oil. Replace the oil with flushing oil, run the engine up to normal working temperature (probably around a half hour run but follow the instructions on the tin), drain out the flushing oil and replace with regular oil. Do not throw out the flushing oil, let it settle and it can be reused.
Bob