Re: what did you do to your motor bike today?
The cheap 4-bolt Chinese freewheels on my chainring sprockets have always been very wobbly, even the new ones. I bought them because they bolt directly onto pocket bike sprockets, which work well as chainring sprockets. When I ran over something on a wet road, it broke my engine chain and front derailleur. It also damaged the freewheel, which is a bear to remove without damaging the threads it's screwed onto.
I just happened to have an SBP HD 5-bolt freewheel, so I decided to install it. The 'wheel and sprocket were taken to the machine shop, who were unable to drill a 4-bolt pattern onto it. After sleeping on it, I realized it was easier to redrill the sprocket's softer metal to match the SBP freewheel. Using the 'wheel as a template, the pocket bike sprocket was easily drilled to match. Five M5 bolts and washers were purchased and both chainring sprockets were reassembled and trial-fitted onto the bike. New SBP crank arms were ordered, and a used 4-bolt freewheel was temporarily installed on the bike to keep it running.
The chain tensioner wheel was extended 1/2" further out today. I'm also working on a simple mount for my engine tach.