Lil' Brother won't start

[pkastagehand]

I have a Briesch Lil' Brother 3/4" x 3/4" I.C. hit n miss that I built back in the late 70s, early 80s. The only time I've been able to get it to run at all was for a short time using an o ring as a piston ring. I couldn't get a cast iron ring to go on without breaking. I made a new piston to with tighter fit but still no run. Fires but won't run. I'm thinking now it could be ignition as much as anything else. I used the spark plug that came with the castings. Maybe a better quality plug will help. The other issue may be points that aren't consistently contacting.

Any thoughts.