I'll ask this question here both because I know you folks and because many scale fans prefer four strokes over those whiny two strokes.

A couple of months ago I bought a used Magnum .52 FS. I tried to get it running once with no luck. The compression however seems very weak compared to my other Magnum .52 FS. Now I know absolutely nothing about engines (model or otherwise) so I'm wondering what might be the cause for the lack of compression and what might be done about it?

Thanks.