Fixing an old vintage dirt bike

"It’s a 1994 Honda CR125 vintage dirt bike. This is the exhaust. Pro Circuit make them in raw steel which means they often get surface rust. Dirt also get impregnated into the steel as it gets hot. The use of WD40 actually penetrates the surface rust and dirt, and then by using scotchbrite to rub it, it lifts the rust/dirt and it’s able to be squirted off with more WD40. Then repeat and wipe with a clean cloth. Always finish by coating the entire exhaust with more WD40. I used less than 1 can to do this. My son filmed and edited the video. He’s 13 and also rides dirtbikes and has helped me restore the white 1988 Yamaha YZ 250 you see in the background. We used the same process on that exhaust. He loves it and loves seeing the rusted parts transition to new again!"