Dropping Cylinder

[traindrv]

I have a 2006 90 HP Mercury 3 cylinder 2 stroke. When I go from idle to WOT it gets to about 4800 RPM it feels like it drops a cylinder and RPM's drop to around 4000. If I slowly open throttle to WOT about 80%-90% of the time it will run fine. I first thought had coil bad but not sure now, any ideas?

[boats.net]

Sounds like a fuel issue, is it fuel injected or carbureted?

[traindrv]

It is a carbureted 2 stroke.

[traindrv]

I figured if it was a fuel issue it would do it more consistant at full throttle.

[boatmangc]

I figured if it was a fuel issue it would do it more consistant at full throttle.

Not necessarily, if a float level is a little low the related cylinder can surge.
If it is fuel it will damage the motor quickly, your fuel is also the source for lubrication in that motor.

[traindrv]

What is needed to do, tear all the carburators down?

[boats.net]

Yes the best way is to disassemble the carburetors, inspect/replace/adjust, clean and reinstall.

[traindrv]

Ok, I have already installed new fuel lines, a water seperator and have a new Mercury fuel filter ordered along with carbruator gaskets.

[boats.net]

If the problem persists then start testing the ignition system, start with the coils.