Mercury 2 Stroke Compression Test

Agustus 15, 2021 Posting Komentar

To perform this test at home you will either need a remote starter button or a friend who can turn the ignition key with the kill lanyard removed. The leak down test does a wonderful job of checking all of the elements in the engine.

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Ive never compression tested the 50 three banger but generally you want the throttle at WOT no choke and turn it over 10-12 times or until it stops building pressure.

Mercury 2 stroke compression test. Im going to be running it at least once a season on all of our 2 cycles and probably our 4 cycles as well at least the carbuerated ones. Putting in compression tester 3. I am currently looking at a used boat with a 2002 50hp Mercury 2 stroke engine.

The leak down test is a more positive test that tests the internal parts of the engine. The second method to compression test an outboard uses a single gauge. You should do a cylinder leak down test rather than a compression test.

After the compression test is completed or skipped you can now proceed with your Mercury 2-stroke spark plugs and compression service by installing your new spark plugs. The private owner says the compression test shows each cylinder at 150 PSI which he claims is excellent. The combination of compression with a leak down test will really indicate the true condition of the pistons cylinders rings valves and the head of the engine.

This would usually lead to zero compression on that cylinder. Here is everything that you need to know about outboard compression tests. I have the service manual and their directions which include.

If playback doesnt begin shortly try. Stroke Urgency YouTube In-Stream Ad. Hello As compression is not a recommended test for an outboard engine there are no such specs in the Mercury service manual.

Take it to a mechanic with a leak down gauge and get the testing completed. Compression testing a two stroke tells you very little about the state of the engine. Its highly recommended to always use a outboard repair manual for your specific year and model outboard engine when preforming a cylinder compression test on your motor.

You are a little on the low side at 90 PSI. The Optimax engine can give you a false compression reading. Primary Compression Test Your 2-stroke outboard powerhead is an efficient pump.

A compression test is still the best test for a 2-Stroke engine and should be performed before any repair service is done on a 2 stroke. This cranking with the ignition disabled will also prime the fresh oil around the block reducing friction at startup after the service. Results vary depending on whether the outboard is a Four-Stroke or a Two-Stroke.

Leak down test are only viable options on 4 stroke engines and compression test are no longer even recommend on 4 Stroke Outboards by Yamaha or Mercury. Having two people is handy one to watch the gauge and tell you when its. We used to run ATF at about 25 but that took forever.

Remove all spark plugs and DISCONNECT THE ECUACU. I just had the head seals replaced and I would like a baseline to monitor going forward. Factors that can affect this test will relate to whether the engine is a 2-stroke or a 4-stroke has a computer onboard has a fuel-injection has a starter-motor or is hand cranked as well as how the ignition is disabled.

Im getting jumps of 25 to 40 and I think the stuff is miracle juice. As it comes down again it compresses it and forces it in to the cylinder when the ports open. At cranking speed each coil should be able to produce a strong blue spark across the gap on every revolution.

How to Compression Test on Mercury 2-Stroke Outboard Engine November 17 2016 Repair Manual 2. Any shop should be able to help you with this type of test. Damaged or blown head gasket.

A small air pump is used to pressurize the cavity to 5psi and the pressure is monitored in the cavity for around five minutes. Small Outboard Cylinder Compression Test - YouTube. They dont suck the mixture at least not much like a 4 stroke.

The crankcase must be completely sealed against pressure created upon the down stroke of the piston and the vacuum thats created when the cylinders piston moves upward back to TDC top dead center. This source says modern two-stroke outboards should be in the 90 to 105 psi range. And the one at one at 75-80 PSI indicates there is likely an issue going on with that cylinder.

The steps to follow are basic guidance for this procedure. But its also the cheapest and easiest to assess and if necessary repair. For ease of future removal and to reduce the risk of thread damage to the cylinder head apply a tiny amount of anti-seize compound to the threads of the plug.

The prop removed and the throttle in the FWD wide open position so the cylinders get plenty of air to compress. The pull rope should be very easy to pull when done this way. Re run compression tests.

The suction part takes place in the crankcase as the piston rises. Typically a compression test is fairly straightforward but various outboard types can result in various important complexities. Good results for Four-Strokes should be 180-210 PSI and Two-Strokes should be around 110-130 PSI.

Im guessing youll go to 125 to 130. The only accurate compression reading is a. It can generally be done by your average Joe in his driveway in about 30 minutes unless the head or block surface needs to be machined which can get more complicated.

With this method the cylinder has to be TDC or top dead center in order to get a correct reading. We have seen case after case where good compression reading are dismissed with poor leak down test readings. It was probably user error.

The second gauge will show you how much pressure has been lost. Repeat testing for all cylinders and compare results. One gauge will tell you the pressure of the air compressing the cylinder.

I would like to do a compression test on my 2001 Seadoo CHallenger 2000 with the Mercury M2 240 EFI engine. With the spark gap tester connected to each of the spark plug leads set the Spark Gap Tester to 7 16 11mm. Compression test on Mercury M2 240 EFI - posted in 1418002000X Challenger.

Maybe it is i dont know anything about compresion but that it does indicate the key condition of the engine block cylinders etc. Compression Test on a Mercury Salt Water series 2 stroke on a 2002 Pro-Line About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy Safety How YouTube works Test. The most likely issue with that cylinder is the injectors are clogged and the engine or at least that cylinder is running lean.

Can be tested on the motor with a Spark Gap Tester. If the pressure ends up dropping over the five minute period then there is a leak somewhere in. If the pressure gauge holds steady at 5psi over the course of five minutes the engine is air tight and has passed the test.

However if you watch the end my video below you will see that my 1979 Evinrude 6 Hp cranks easily cold 2 pulls with 60 psi compression This source says the older two stroke outboards below 25 Hp should be between 75 and 85 psi. The compression test should be done with both plugs out of the motor and the plug wires grounded out to the block.

Everything You Need To Know About Outboard Compression Tests