Simply put each piston is placed at top dead center and the cylinder is pressurized through the spark plug hole with the leak down tester. The second gauge will show you how much pressure has been lost.
17 July 8 August 2018 Flight Safety Australia
Outboard leak down test. Dangar marine 24480 views. In this video i show how to perform a leak down test on the yamaha 50hp outboard motor. The gauge measures the amount of air getting past the rings valves or other passages and provides a reading compared with zero leakage. The spark plug is removed. This uses a special set of gauges. Heres a step by step breakdown of the test.
The first is called a leak down test. One gauge will tell you the pressure of the air compressing the cylinder. A leak down test is performed with the engine not cranking. Fuel additive first the engine should be warmed to operating temperature providing it still runs. In contrast to the cylinder leak down test which measures how much pressure is lost in the engine. The internal fuel tank and cover plate are removed to expose t he flywheel.
So far it is looking like there is a burnt out exhaust valve on cylinder one and maybe two but well find. To perform a leak down test you would pressurize the cylinder with compressed air. So the compression test measures how much pressure the engine can produce while cranking. There are two basic ways to compression test an outboard. Performing a leak down test on the yamaha 50hp outboard motor. If the compression is low in a cylinder its time to find out why.
In a cylinder leak down test the engine is placed on tdc of the cylinder in question. The leakdown gauge is hooked up to the compressed. Use the leak down test to know if you should be changing head gaskets valves piston rings or looking for a crack. Performing a leak down test on an outboard marine engine duration. A compression test is a dynamic test engine moving a cylinder leakdown test is a static test engine at rest.
Gallery of Outboard Leak Down Test
