I just received a K&B 7.5 (.45) 9100 D/F series engine from a fellow modeler. My question is , At top dead center, it feels as if there is a flat spot on the bearings (I know there isn't however), It just feels like it. Is this normal for this engine. It also does it at bottom dead center. Just wondering if this is normal. Is it the sleeve or the piston , or should I just inquire about returning it???
Thanks all
Don