Engines smoke

[belliswood]

I have noticed that both of my engines put out blue smoke. They run great so I was wondering if they are running rich and is there an adjustment or not. I have never felt with EFI engines before.

Thanks

Barry

 

[dlvwill]

Blue smoke indicates its burning oil. How many hours?

 

[Ka1oxd]

yup blue smoke is oil being burned. What oil are you using? Is it a lot of smoke? Was this just after you commissioned it for this season?

 

[belliswood]

I have 772 hours on the engines, I have put about 25 hours on since the season started. It is a steady stream of smoke but dosent seem to be using oil. I also notised that when I start them after sitting over night there is some black soot in the water from the exhaust. Is it burning oil or running rich?

Thanks

 

[BlewByYou88]

I have 772 hours on the engines, I have put about 25 hours on since the season started. It is a steady stream of smoke but dosent seem to be using oil. I also notised that when I start them after sitting over night there is some black soot in the water from the exhaust. Is it burning oil or running rich?

Thanks

Black Soot? Sure these aren't diesels!

 

[edsmax]

Blue smoke is "normal" for Gm engines with that much use. Do they smoke all the time even when warm? or do they only smoke when cold? If its that much of a concern, you could always do a compression check and just monitor your oil level.

 

[Bob & Sue]

I have 772 hours on the engines, I have put about 25 hours on since the season started. It is a steady stream of smoke but dosent seem to be using oil. I also notised that when I start them after sitting over night there is some black soot in the water from the exhaust. Is it burning oil or running rich?

Thanks

Black soot is usually to rich of a choke setting especially in carbed engines ( I had that problem with the choke ) it can happen on injected engines also or it could be a symptom of the blue smoke if you have a worn valve stem seal allowing oil down the cylinder at start up it could be burning carbon build up with oil and fuel mixture. Just my opinion I'm not a mechanic.

 

[CliffA]

I have 772 hours on the engines, I have put about 25 hours on since the season started. It is a steady stream of smoke but dosent seem to be using oil. I also notised that when I start them after sitting over night there is some black soot in the water from the exhaust. Is it burning oil or running rich?

Thanks

usually only 3 things can cause smoke from the exhaust:

1. blue smoke = burning oil
2. gray/black smoke = rich fuel/air mixture
3. white smoke = burning(vaporizing) water or coolant

if you are not seeing the oil level drop over a period of time the smoke is likely from either #2 or #3 above....if you are seeing black soot marks on the transom at the water line you likely have issues with the air/fuel mixture being too rich...

cliff