DF140 Compression Difference

[jman1230]

Hello all,

Sorry to bother everyone again but hopefully someone will know some advice. My year motor is a 2003 and my spec book says compression should be between 171-228 psi with a max difference of 14. Mine reads from top to bottom: Cylinder 1=120psi, Cylinder 2=80psi, Cylinder 3=150psi, and Cylinder 4=150psi. Any advice? I thought maybe I could Check the head gasket and see if it looks bad. Other than that, its pretty much time for a new power head right?

Thanks in advance for any help,
Josh

[hentree56]

if the engine was warm and you did the test with it wide open throttle, then yes its probably time for a new power head. i'm guessing if you had reason enough to check compression you were probably already thinking that. if they were all 150 you'd be fine but that 150 to 80 gap is huge and throws off the balance of the motor which is just gonna cause more problems the longer it is runs.

[boat3310]

How many hours are on your engine ? Was it burning oil ?

[noelm007]

Is the motor running OK? why did you do the compression check? did you repeat the tests and the results were the same?