Exhaust smoke?

[pearl111]

When a small lawn mower motor
or predator 212, or Briggs & Stratton Flathead five hp ect. ect. Blows blue or white smoke out the exhaust.

Is that an indication that the rings on the Piston are burnt or used up?

Or could it be something else?

Thanks

 

[Denny]

Rings, or valve guides will cause blue smoke.

 

[pearl111]

My brother said he had a lawn mower and it had very low compression.

And it also blew out a lot of blue smoke from the exhaust.

So I'm .....guessing..... that it's probably the rings are worn out on the piston.

 

[Master Hack]

I have a new predator that belches blue smoke until it warms up. Modified beyond the point of returning it.
Lucas oil treatment at 25% solved that problem.
Finest chinese quality. It does however, run nicely.

 

[landuse]

Rings are probably worn

 

[Hellion]

I have a Briggs OHV 16.5 HP that I use to spin some blades and power two wheels to cut grass. It's a riding mower, 23 years old and the engine is really tired at this point (it's starting to seem like a long-term "how long will it last?" experiment) so it belches out decently awful clouds of blue/white smoke on startup .... but only until the piston and rings or whatever seals up the (ring) gaps via heat expansion. After that, no more smoke.

I did switch to single viscosity 30 SAE lawnmower oil some time back and it certainly makes a difference, as a multi-viscosity oil (5W-30, 10W-30 etc) does indeed cause a little more oil consumption and a propensity to leak past the crank seal (the mower marks its territory).

Change that oil! How many people do this religiously? This mower gets an oil change every 25-30 hours (about an entire mowing season) and this just happens to be the Briggs OCI (oil change interval).

 

[65ShelbyClone]

When a small lawn mower motor
or predator 212, or Briggs & Stratton Flathead five hp ect. ect. Blows blue or white smoke out the exhaust.

Is that an indication that the rings on the Piston are burnt or used up?

Or could it be something else?

It's an indication that oil is getting burned; the cause is less straightforward. It could be from the cylinder, the valves, or even the crankcase breather.