What should compression be on 2 stroke outboard?
Two-Stroke engines should have a compression reading of around 110-130 PSI. Sometimes having compression as low as 80 and 90, the engine will still run great!
What should the compression be on an Evinrude crank?
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. This source seems to confirm with my understanding that 60 psi in older outboards can sometimes be OK.
What should mixture ratio be for 1964 Evinrude?
1964 and newer use 50:1 New engine break-in (not direct injection) requires 25:1 Please note that some Johnson and Evinrude Owners Manuals mention 100:1 mixture ratio after the motor is completely broken in, but most experts suggest against doing that. Stick with 50:1 for the 1964 and newer motors.
What should the PSI be on an outboard compression test?
Results vary depending on whether the outboard is a Four-Stroke or a Two-Stroke. 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. How to do them and what the results mean for you! What Is A Compression Test?
What should the cylinder compression be on a Mercury outboard?
From my research, cylinder compression values that people say are “acceptable” for low horsepower outboards seem to vary. They not only vary from the reporting individual but from manufacturer to manufacturer. For instance, a fully functional Mercury 25 Hp cylinder compression value may be significantly different than that of a Johnson 25 Hp.
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. This source seems to confirm with my understanding that 60 psi in older outboards can sometimes be OK.
1964 and newer use 50:1 New engine break-in (not direct injection) requires 25:1 Please note that some Johnson and Evinrude Owners Manuals mention 100:1 mixture ratio after the motor is completely broken in, but most experts suggest against doing that. Stick with 50:1 for the 1964 and newer motors.
What is the PSI of a 1989 Evinrude?
I have a 1989 15hp Evinrude, same powerhead as 9.9, with about 600 hours on it. Shortly after a thorough decarb, it has 104 psi on the top cylinder, and 106-107 psi on the bottom cylinder, when taken on a warm engine. The calibration of the gauge was verified within a couple of weeks before the reading was taken.
Results vary depending on whether the outboard is a Four-Stroke or a Two-Stroke. 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. How to do them and what the results mean for you! What Is A Compression Test?