I recently took my boat into get a new injector replaced. (2nd one in 1.5 years) I run ethanol free gas along with fuel addative but unfortunatly I'm still replacing injectors. (hopefully just fixing previous owners mess ups). Motor has roughly 350 hours on it and is a 2008 115 etec jet prop. While in at the mechanics getting the latest injector installed they mentioned they did a compression test while they had the computer hooked up. He stated that 2 cylinders had 120 compression and the other 2 had 135 compression. Are these compression statistics above the Evinrude recommendations? I am aware of the 15 percent difference and my difference is only 8.5 percent so I believe I am good there but unfortunatly I cannot find normal compression ratings for the etecs anywhere. Does anyone have any insight into this? Thanks in advance.
Solved! Go to Solution.
There are no specific numbers for Evinrude outboard compression readings as there are too many variables that affect the test. The service manuals call for a 15% difference or a 15 psi difference between cylinders depending on the engine.
If you perform a decarbonization using Evinrude Engine Tuner you may find that the compression numbers may increase after freeing up any carbon stuck piston rings.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.