Actually, I have it checked yesterday mainly to check the plug seal but it was still ok and without signs of leak. What I notice is that when you switch on the engine and try to open the oil lid, and place your hand on top of the open lid, you will feel air pressure coming out and makes a sound. I don't know how to test a simple compression test for engine. Do you know where to bring my Revo for this type of test? Sa Servitek kaya kaya nila? How much kaya?