Boat Motor Compression Chart

Boat Motor Compression Chart FAQ

How much compression should an outboard motor have?

Good results for Four-Strokes should be 180-210 PSI, and Two-Strokes should be around 110-130 PSI. Here is everything that you need to know about outboard compression tests.

What should the compression be on a 2 cycle boat?

Older two cycle outboards, especially low horsepower, can run fine around 60 psi however above 90 psi is optimal. Four stroke/cycle engines produce much higher compression. The main thing to check is the difference between cylinder compression. Cylinder-to-cylinder compression readings that differ more than 10% reveal trouble.

What is a compression test for an outboard?

What Is A Compression Test? A compression test for an outboard is a simple test that can be performed on any combustion engine. It is the very basic test that can provide the tester with the viability of the engine itself. It will prove whether the engine has a good powerhead or not.

How to check compression on a mercury 2 stroke outboard motor?

How to Compression Test on Mercury 2-Stroke Outboard Engine 1. Begin by disabling the engines ignition system by disconnecting the lanyard clip. If your motor is not equipped with... 2. Extract all the spark plugs from the motor and keep them in the order of which they were removed. Examine the ...