How much smoke is normal?

[l008com]

My engine is a 1989 Mercury 90hp, 3-cylinder, 2-cycle. It has it's own internal oil tank and it blends the oil itself.

So how much smoke is normal? This engine has always smoked when it was cold. But more and more, it seems to smoke all the time, not just when its cold. Given that it's carbureted, it probably doesn't help that I practically never have the chance to open it up any more (stupid no wake zones). And the engine runs really well too. But it just seems to smoke a lot, at all points in a 3 hour boat ride. It's not like you're in a constant cloud of smoke. But any time you stop, things can get smokey. Especially when you're in a lock.

So is there anything I can check? Anything that could be going wrong and causing excess smoke? Based on my limited knowledge, the thing that would cause excess smoke would be too much oil being mixed? Is there a way to check/adjust the blending mechanism in the motor? Or am I barking up the wrong tree here?

 

[MH Hawker]

have you changed the plugs that can often cause more smoke or use some of the synthetic oils

 

[l008com]

I was using synthetic but last spring I had some oil lines replaced and that included a fresh gallon of oil, I wonder if that oil is NOT synthetic, maybe that's why it seems like more.

Also are you saying changing your plugs can make it smokier, or not changing your plugs can make it smokier? Either way, my plugs aren't brand new but they're still pretty clean.

 

[MH Hawker]

older plugs can carbon up and smoke more

 

[ondarvr]

A thermostat that's stuck open and causing it to run cold.

Type or brand of oil.