Please teach me about the leak down test and what tools do I need. Is this like a compression test? I notice that you all talk some about the 2-cycle leak down testing. I use to perform compression test on all mowers that came into the shop. If it was low I would take the head off and check the valves and piston. I would clean out the carbon and lap the valves. I would check to see if the cylinder walls where scored. Teach this old man.