Hello, I have 2 O.S. powered vehicles, Revo (18TM) and HPI RS4 (.18CV-RX). First of all, I love my O.S. engines. They hold a tune very well and hardly go through any glowplugs. My problem is "stuff" leaking from the front bearing. By "stuff" I mean I don't know what it is. I notice a line of dirt on the body that is directly in line with the front of the engine as it's being slung outwards from the force of the engine. I can only assume that it's fuel leaking. Both engines do this and neither have any problems. One thing the .18TM does different is around the dust boot on the carb slide I see "stuff" gathered around the end. Like I said, both engines are running fine, this is more of a nuisance than anything. I have sealed both engines to the best of my ability. This is the only part I don't know how to fix. There may not even be a fix but I need to know if there is a way to stop it. Thanks!!!!