I set all my engines to run perfect. They do and when one of them starts acting stupid and its hard to keep a setting or a good idle. I change or check the plug first to see if that takes care of it. Most of the time it does. There are many things that can cause an engine to run poorly. If your engine is not "properly tuned", you can be chasing shadows. I fond that many people do not have peoperly tuned engines. They think they do but are way off. Whenever I ask if they checked what they adjusted, they don't know whatI am talking about.

They we have guys with problems and they add or change things which only maks the orignal problem. It may seem like youcured it but you didn't, you only changed things a bit.