After the 25 hour inspection question, Spark plugs

Hello, just wrapping up the inspection, cylinders 1 and 2 spark plugs were black with a good clean electrode, cylinders 3 and 4 very clean like they never have been firing. Engine has 27 hours on it and develops full power. Is this normal since the front 2 cylinders probably get better cooling and the back two cylinders run hotter. Maybe a mixture problem or nothing at all. My first time inspecting plugs on a rotax, any comments. Thanks Don

I saw the same thing early in testing the RV12.

Asked the local Rotax dealer (LEAF) about it. They said the geometry of the intake manifolds provides even distribution at high rpm but at lower power settings it is normal for the front two cylinders to run rich.

Spark Plugs

Thanks for the info Keith.

912 Plugs

Make sure your carbs are Sync'd really good..