I found this mess on ebay. The guy had the engine for sale and I asked if he had the frame. He did. Brought it all back for $700 It's a 1980 frame and a 1982 490 engine. Rod bearing went bad and it was taken apart and there it sat for years. It had a dish towel for an air filter and a licence plate reinforced seat base. Frame was crack free but needed to be blasted.The engine was better than expected. S/N 3540053. No tranny parts needed to be replaced. Cases were good. I changed all the bearings and put in an early 400 crank. Bore was fresh and piston new. (Got lucky on that) Frame was stripped and modified for '81 plastic, seat and pipe. Computer made paint to match Vintage Iron plastic. I grabbed an '81 swing arm from ebay. Laced up the new Excel rims right here with stainless spokes. Rear hub was bad. Steel brake liner popped out. Don't over adjust those drums! Tank and air box painted with an epoxy urethane combination.A 40mm Mikuni works perfect with the stock bing cable. VI pipe and silencer. I adapted an '06 RM 2 stroke ignition and it runs clean. After the first test ride, I couldn't stop laughing. Having bought a CR 450R new in '81, I had no idea what I was missing.