To RCIGN1:

I hear you loud and clear. That's the precise reason that all the engines I fly are industrial derived - about ten in all. Right now I am in the market for a good 100 cc engine, and of course the DA100 seems to be the popular choice. However, the BME 5.8 single and the Brison 5.8 single costs a lot less. I am leaning toward the Brison 5.8 but I don't like the linkage set-up for the spark advance. Yet, I understand this engine is available with true electronic spark advance, so that solves that problem. Now - in your opinion, which of the three has the guts to last a lifetime? I hate to buy an engine that constantly needs to be returned to the factory for repairs, even though they do it quick and economically.