20hp mercury low compression

[deanwerden]

we have a 2001 20hp that I guess in hind sight ways had a bit of a weak stream at idle and this year at wide open I ran out of gas and when I restarted the motor would only go about 5 mph. I'm thinking if It was already running on the hot side and maybe went a bit lean when I ran out of gas ?

so I have 120 psi on the bottom and 90 on the top but have read that these things are virtually non rebuildable due to the aluminum blocks that have no chrome or nikasil bores.

we have already purchased a new 25 horse merc but would like to get as much out of this $$$ to put towards the new motor

 

[Faztbullet]

You should have the Mercosil block and it is boreable but it takes special tooling/diamond stones add most shops cannot do it...