running rich does not cause dirt to get sucked into the engine...that is complete nonsense ! the only thing the leaking can do is cause dirt to collect, being rich doesn't make them suck it in..being lean causes them to suck dirt in.............. fuel is what seals these engines , when the tune is lean there is no longer enough fuel to seal and thats when the engine starts to suck dirt... the whole idea that leaking out the front causes them to suck dirt is 100% WRONG !!!! obviously whoever came up with this theory doesn't understand how these engines operate and how they seal themselves....