Compression for Mercruiser

[Bob McDonough]

Good morning all,

I have a question related to a 2002 Mercruiser 5.0 MPI bravo 3. While putting it to bed for the winter it was hard starting and running rough. What should compression reading be?

thanks in advance!

 

[scoflaw]

170-180. I've had cracked heads, between the 2 center exhaust valves, that gave me a 150 reading

 

[MickT]

readings should all be fairly close together - a difference from the rest is far more important than the actual numbers as such....

 

[CliffA]

readings should all be fairly close together - a difference from the rest is far more important than the actual numbers as such....

+1.....I agree this is more important than the actual compression number.....the closer all cylinders are to each other the better.......

cliff