This is a 1978 Yamaha DT175 off to Atlanta Georgia. This engine was a train wreck! One of the dirtiest engines I've had to deal with. The ultrasonic cleaner made short work of the cleaning. One of the biggest problems was the crankshaft. The seal surface was pitted to the point that the seals would never hold the case pressure. I welded the seal surface and machined it back to factory specs. New connecting rod, bearings, piston, gaskets, seals and expert assembly. Check out the plastic side covers. They were grey and sun faded. I have a process to make them look new. I hope the rest of the bike looks like the new engine.