Mercury 40hp 4 stroke Idle problem

[watercreature]

Runs great at speed, kills when at idle or slow troll speed. Changed plugs, fuel filters, and oxygen intake valve. Still doesn't fix the problem. Any ideas on what else could be causing this. Thanks.

 

[Texasmark]

How about some history on the engine with compression being a main question.

 

[watercreature]

How about some history on the engine with compression being a main question.

When the fuel filters and plugs were replaced, the compression checked out good. When this failed to correct the problem, I tried replacing the air solenoid, unfortunately that didn't help either. Only run non ethanol gas. It is a 2018 motor.

 

[watercreature]

How about some history on the engine with compression being a main question.

Any other Ideas Texasmark,

 

[racerone]

Maybe it is running on 2 of 3 cylinders??----So test for strong spark on each lead.----The term " good compression " means little to some.----So post the actual numbers.