Mercury xr6 loss of power

[Grooms19]

Hey guys, have a 2001 procraft 180 sf with a 2001 mercury xr6 on it. The boat has a loss of power on acceleration and full speed. Max rpms around 3700 plained and max speed of around 30mph with 2 people in the boat. The boat idles fine. Trying to figure out possible solutions to this. Thanks

 

[jimmbo]

Compression, spark, and fuel are what it takes to get your motor to run. At least one of those is not cooperating.

First thing to do is a compression test. Good spark, at all throttle settings.
Is that engine carbed, or a fuelie?

 

[Grooms19]

Its carbed. I turned over motor outside of water and can increase rpms like normal. One strange thing was that one of the spark plugs looks like it is brand new, while the other 5 have signs of use.

 

[jimmbo]

Maybe that cylinder is not getting fuel. If so, it's not getting oil either. Revving an engine out of the water, or even in the water proves nothing. Out of the water, more than half the cylinders can be dead, and it will rev like no tomorrow

 

[Grooms19]

Ok, I will check compression in the morning. Hopefully all good there.

 

[Grooms19]

0 compression on #2 cylinder.