I have an Evolution 61 on my 4-Star and has been running beautifully for the past 3 years with no problems. Today after flying I noticed my plane was all black. 2-Strokes leave your plane all oily, but this is black ! Muffler is tight. Any ideas ?

It might be something as simple as the baffle inside the muffler...they sometimes loosen up and vibrate around..causing the exh. oil to turn gray. The loose baffle is a common occurance with Evolution engines.

Take the muffler apart and get rid of the baffle...then test run it...

Or...it could be something more serious...like the engine is eating itself...bad bearings...etc.

Aluminum fretting.

Here is the glow engine forum: http://www.rcuniverse.com/forum/forumid_114/tt.htm

warranty expired [:@][:@][:@]

I'll try the baffle thing first. Thanks.......

Hi!
If it is metallic grey black ...it's just something that is loose and rubbing against sometging, most of the time a loose silencer (alumium rubbing against alumium)! Simple as that!

Found the 2 halves of the muffler a little loose. All tightened up now. Going to run it this weekend and see what happens. Thanks everyone for all your help and replies.

How did things check out ?

Had to work this week, didn't have time to run it. Supposed to rain this weekend, but I'll try depending on weather. Thanks......