I stripped the paint off the swingarm. For some reason, somebody did a crappy job of painting the YZ125C swingarm white, and much of the surface was rusty and corroded where both the repaint and the OE black were worn off. Before doing any work on it, I wanted to strip it. Since I was doing this in my basement garage, which is directly under our kitchen and bedroom, I bought some odor-free “Citristrip.”
Since most products that promise greater safety and fewer harmful fumes also tend to be generally less effective, I wondered if a product designed for stripping wood furniture would be able to tackle OE frame paint. It went on easily enough and was thick enough to cling well. Here’s a hint: use a natural bristle brush, not one of the cheap foam brush I used — not only could it not work into crevasses well, but as I was working with it, the stripper dissolved it into goo!
The instructions said to let the stripper work for “up to 24 hours,” but I was really just testing whether it was going to work at all, so I only gave it about 40 minutes of soak time. Then, I pulled on the rubber gloves and scrubbed it haphazardly with a green scrubber sheet for all of about 90 seconds, then hosed it off in the driveway. Amazingly, despite a pretty slap-dash application and not much “cooking,” nearly all of both coats came right off.
It needs another application, especially underneath the bottom where I hadn’t bothered to coat it, but I was very impressed with the job Citristrip did.
Thinking through how to make this swingarm work is still what is slowing this build down. (Well, that and the fact that I am spending no appreciable time or money on it!) There’s really no point in doing anything else until I have nailed down precisely how I want to mate the swingarm with the frame and engine. As many different designs as I’ve uploaded to this thread, there have been just as many variations since that I’ve investigated and abandoned. Unfortunately, I also discovered that the Bultaco Matador rear engine mount I bought off Ebay won’t work with my Pursang frame; even though the engine cases are the same, the position of the swingarm pivot relative to the engine is just slightly different. Grrrr. Perhaps I have more mounting plates to make.
What I’m realizing is that that this swingarm is really not an optimal choice for this build, even though it was the starting point for the whole idea. The pivot diameter is too narrow, the shock mount is too wide, and the whole thing looks pretty cobbled. I know many shadetree amateur weldors who wouldn’t be satisfied with boogered-up welds like these:
