John Deere GX345 puffs blue smoke on startup

[Dandy]

My John Deere GX345 puffs blue smoke on startup. It puffs a small cloud of blue smoke and then clears out could it be the valve seals or somthing else? It only has 270 hours on it and has been well taken care of.

 

[Lawnranger]

Could be rings or valve guides. You can try a leak down test but if the valves seal well and the valve guides/seals aren't doing their job a leak down test will not tell you the condition of the valve seals. My mower does the same thing but the smoke is a little more black from the rich mixture of the choke being on for a few seconds during start up. Check the oil level and fill exactly to the full mark then keep an eye on the oil level. If you have a moderate to severe problem the oil level will consistently be low as a result of oil consumption. Is the spark plug getting oil fouled?

 

[Dandy]

I never have to add oil it stays on the full mark. The spark plug looks nice and dry no oil.

 

[Lawnranger]

I never have to add oil it stays on the full mark. The spark plug looks nice and dry no oil.

Every engine uses a small amount of oil and burns it in the combustion process but most use so little that it is hardly noticeable. Yours sounds normal and the puff of smoke may be nothing to worry about. If this were my engine I would not be concerned with it until I see a noticeable loss of oil on the dipstick between oil changes or the spark plug starts fouling. Like I mentioned earlier, my mower engine has a puff of smoke every time it is started cold and goes away after a few seconds of running.

 

[Practical Consumer]

Doesn't sounds like anything to be too concerned about. If you want to investigate it further try removing the spark plug and cranking the engine a few times before start up. This would clear and oil that may have creeped into the cylinder. Replace the plug and start the engine. If it doesn't smoke that should verify that oil is getting into your cylinder. Do you store your engine at an angle?