YT-7300 Petrol engine compression tester
Description
Suitable for all types of spark plugs.
Warning! Do not touch exhaust pipes, radiators or any other hot engine parts, as this may cause a reflex hand movement in the opposite direction and, as a result, injury from striking other engine parts.
TEST PROCEDURE
Run the engine for approximately 15 minutes to reach its normal operating temperature.
Switch off the engine. Disconnect all leads going to the spark plugs (one by one) and mark the connection points so they can be reconnected correctly after the test.
Unscrew all spark plugs by 1 turn, then use an air hose or tyre pump to remove dirt that has accumulated around the plugs and gaskets. Place them on a clean flat surface, keeping the order in which they were removed. This makes it easier to diagnose problems related to compression and spark plug condition in individual cylinders.
Remove the air filter and lock the carburettor throttle plates in the fully open position. Remove the high-tension lead from inside the distributor and earth it. To disable the electronic ignition system, disconnect the electronic ignition module or remove the battery terminal from the distributor cap (on V8 and V6 models, disconnect the battery lead from the distributor cap).
Screw the adapter hose into the spark plug holes. Tighten by hand only - DO NOT USE A SPANNER!
Then crank the engine with the starting handle for at least 4 compression strokes or until the pressure on the gauge scale stops rising.
Record the pressure reading and repeat the procedure for the remaining cylinders.
TEST RESULTS
If the cylinder is working normally, the gauge needle should move up with each stroke until it reaches its extreme position. Results for all cylinders should be within the manufacturer's specification for the engine, and the difference between individual cylinders should not exceed 10%.
If the gauge needle does not move up normally or, after several strokes, does not change position and then starts rising, a valve is sticking in the cylinder.
If the compression pressure reading is much higher than the engine manufacturer's specification, a significant amount of carbon has built up in the cylinder. In some cases, using a spark plug with a higher heat range helps solve this problem.
If the reading on two adjacent cylinders differs from the other cylinders by 20 psi or more, the head gasket is damaged. There may be water and/or oil in both cylinders.
If the test results are low or uneven across cylinders, pour a teaspoon of SAE30 oil into each cylinder and run the test again. If the results rise significantly, the problem is incorrectly fitted or worn rings. If the results stay the same, the valves are damaged.
Reconnect all spark plug leads in the established order. Connect the secondary winding lead to the distributor and return the carburettor throttle to the normal position before the next engine start.
Warning! Do not touch exhaust pipes, radiators or any other hot engine parts, as this may cause a reflex hand movement in the opposite direction and, as a result, injury from striking other engine parts.
TEST PROCEDURE
Run the engine for approximately 15 minutes to reach its normal operating temperature.
Switch off the engine. Disconnect all leads going to the spark plugs (one by one) and mark the connection points so they can be reconnected correctly after the test.
Unscrew all spark plugs by 1 turn, then use an air hose or tyre pump to remove dirt that has accumulated around the plugs and gaskets. Place them on a clean flat surface, keeping the order in which they were removed. This makes it easier to diagnose problems related to compression and spark plug condition in individual cylinders.
Remove the air filter and lock the carburettor throttle plates in the fully open position. Remove the high-tension lead from inside the distributor and earth it. To disable the electronic ignition system, disconnect the electronic ignition module or remove the battery terminal from the distributor cap (on V8 and V6 models, disconnect the battery lead from the distributor cap).
Screw the adapter hose into the spark plug holes. Tighten by hand only - DO NOT USE A SPANNER!
Then crank the engine with the starting handle for at least 4 compression strokes or until the pressure on the gauge scale stops rising.
Record the pressure reading and repeat the procedure for the remaining cylinders.
TEST RESULTS
If the cylinder is working normally, the gauge needle should move up with each stroke until it reaches its extreme position. Results for all cylinders should be within the manufacturer's specification for the engine, and the difference between individual cylinders should not exceed 10%.
If the gauge needle does not move up normally or, after several strokes, does not change position and then starts rising, a valve is sticking in the cylinder.
If the compression pressure reading is much higher than the engine manufacturer's specification, a significant amount of carbon has built up in the cylinder. In some cases, using a spark plug with a higher heat range helps solve this problem.
If the reading on two adjacent cylinders differs from the other cylinders by 20 psi or more, the head gasket is damaged. There may be water and/or oil in both cylinders.
If the test results are low or uneven across cylinders, pour a teaspoon of SAE30 oil into each cylinder and run the test again. If the results rise significantly, the problem is incorrectly fitted or worn rings. If the results stay the same, the valves are damaged.
Reconnect all spark plug leads in the established order. Connect the secondary winding lead to the distributor and return the carburettor throttle to the normal position before the next engine start.
| Weight, kg | 0,188 |
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