17HP Lawn Tractor Engine Started blowing Blue/Gray Smoke - Intermitantly??

[Beltzington]

4-Cycle Kawasaki engine has 700+ hours on it, I have performed regular oil changes. About 50-hours ago I noticed on initial cold startup it blew blue smoke for a few seconds, no big concern likely a little valve wear was letting oil into the cylinders. However, during last two startups the blue smoke was visible even after running for several minutes, not good I thought, likely more permanent valve damage or the rings are going. I haven't done any compression check to isolate the issue to a specific cylinder because both times I shut the engine off and restarted it stopped blowing smoke.

Engine runs fine other than the pollution, any ideas on what could be causing the problem that seems to magically fix itself after restarting a warm engine?

 

[radios1]

if not the valve guide seals, or the oil control ring, perhaps the fuel injectors are making it too rich, and the diesel is not being completely burned..

 

[Beltzington]

if not the valve guide seals, or the oil control ring, perhaps the fuel injectors are making it too rich, and the diesel is not being completely burned..

Sorry I did not clarify this a gasoline, carbureted engine. Thanks

 

[radios1]

Sorry I did not clarify this a gasoline, carbureted engine. Thanks

okay, then bad valve guide seals, or oil control ring, if the ring, then, it requires a complete stripping of the block, and boring or honing, then replacement of ALL the rings and piston, and a cleaning with first kerosene, then a soap and water mixture, then a coating of oil, THEN the rings and piston go in.. hopefully, it's a quick and cheap replacement of the valve guide seals that is needed, much cheaper.. sometimes, replacing the crankcase oil with 100% synthetic oil, like Mobil1 will reduce, or eliminate the oil burning for a while, anyway..

 

[Alien]

If the choke is stuck on a bit the motor will blow smoke. If it was rings or valve stems it would be consistent, not stop when you restarted it. At those hours it is highly unlikely that it would be rings or valve stem seals on a Kawasaki.
Check the air cleaner isn't clogged up as well.