I have a 1980 Yamaha QT50 that i found behind a barn in the weather for 20+ years in Chappells South Carolina. its all original and everything was there. it only has a few spots of surface rust, and the engine was locked up solid after 2138 miles (mostly packed with dirt because it was half way in the ground) I have tried to keep it mostly original, so i beat the piston with a sledge hammer and a peice of wood to remove the cylinder and broke the crankshaft free with a Ratchet. i cleaned all the dirt, rust and creatures that lived in that poor ol' qt50. then i cleaned the carb it was bad, the tank was no better it was packed with mud, and the air cleaner box had a hornets nest. after i cleaned it all i ran 40:1 mix fuel to the tank and tried to fire it up, and i heard that engine pop, then i kicked the starter about 15 more times and then it finally fired up after 20 years sitting untouched but it ran all the way up to full throttle and i found out that the carburetor slide got seized at full throttle so i had to replace it and now it runs and drives pretty good, both of the old Yokohama world tour 953's hold air so for now i'm running on them. it has working lights cause they turned on when it fired up for the first time. Trust me it was very bad but i got it going and brought it back to life.