It's been a couple months since posting here since there wasn't anything interesting to post. Well, just yesterday I decided to take the OS out of the plane for inspection and general maintenance. It has about 10 gallons of gas through it, some 50 hours of actual run time so it was due.

Spark plug...... slight build up of brownish stuff, lead probably; avgas is low lead, not no lead. Easily cleaned

Top of piston........ similar slight build up; scraped off with a piece of plastic

Rest of piston......... almost pristine; very clean

Head........ super clean; no build up at all which surpised me a bit; I've been running fairly large loads on the engine and thought I might be running it rich to haul the load. Not so!

Liner........ pristine

Con-rod and bearings......... pristine......Actually the whole lower end is super clean looking brand new. I was quite pleased. Probably should have taken photos but simply forgot

I've run other gas engines that haven't fared as well after 50 hours of operation. The OS engine continues to impress!!!