Kohler Command CV15S Blue smoke when cold

[GhostFlame]

Wow, Last week I changed the oil and filter in this engine. (Kuboto 1670t) I Used Napa 10-40 conventional. which is what I've always used and meets manufacturer specs.
I have about 450 hours on this engine. After sitting in the shed for about a week, When cold a large amount of blue smoke came billowing out and kept puffing until the engine got hot maybe 3 or 4 minutes. Outside temp was 95 F. This is new behavior.

What would cause that in such a lightly used engine? Another note I change the oil and filter every year at the end of June. I also put in a new plug and air filter.
purchased new in Oct 2002

could it be valve seals or is it something else.

 

[123Saab]

Stuck rings?

 

[spasm3]

I've had this happen in a 25hp briggs engine in my previous lawn mower. It would do this at the beginning of spring or when it sat a month without running. The piston was probably at the bottom of the bore for a while on one of the cylinders and was not sealing at the top of the bore until it ran a bit.

 

[Cujet]

Any possibility of being overfilled?

I generally don't worry about blue smoke on startup with OPE. Especially with horizontal engines. It's common for oil to sneak past components after shutdown.

However, it's possible that it's simply consuming oil, either through ring seal or valve guide issues. Remember, air cooled engines are more likely to have cylinder distortion and ring seal issues, or ring overheating and loss of tension. If that's the case, keep an eye on your oil level.

There are a number of examples of these engines failing, possibly due to low oil level. My neighbor across the street had one fail after a few seasons of mowing 2 acres. Connecting rod went through the case. While the engine looked new, I'm not sure it had any oil in it by the time it failed.

 

[JTK]

I'd guess at it being slightly overfilled or it was parked such that over time, crankcase oil pooled in the valve cover and was forced out the breather and into the carb on restart.

REAL common on vertical shaft riders that are parked nose-down for any length of time.

 

[Slick17601]

My CV16 does the same thing, but not every time. It burns no oil that I can tell on the dipstick using Quaker State synthetic 10w30.

 

[GhostFlame]

Thanks for all the replies.

I let the oil drain overnight and put in 2qts after removing and changing the filter. The book calls for 2 qts.
I will check the oil level.
It wasn't parked on an angle my shed has a level floor.

If this continues should I have it checked for rings or valve seal leakage? I sure as heck don't want to put a rod through the side of this engine. I did a top of engine rebuild on a Tecumseh last summer. Not that it was hard but its a PIA for someone like me.

I'm meticulous on maintenance on my machines most people think this is a new machine. It cuts half acre landscaped property about 35 times a year about 1 hour each time, say we round it up to 40 hrs per year.

 

[GhostFlame]

Oh yeah, can you blame it on the NAPA dino 10/40? I honestly don't think so but, ...

I have always used dino oil (in this engine) usually whatever meets the spec that is cheapest. Sometimes it's a name brand but often it a store brand... never a problem before.
I suppose I could use synthetic but with only 40 hours OCI, seems like that would be a waste.

 

[JTK]

Is this a vert or horizontal shaft 15hp?

Like said, vertical shaft will often smoke intermittently if you run the 2 full quarts of oil in them. Lowering the level to the midway mark on the dipstick will help if this it the issue.

I wouldn't even consider a tear-down unless it consumed oil like a mofo, or sounded and/or ran like poop.

 

[SteveSRT8]

I just replaced a Briggs 16 hp single with a 26 hp twin platinum series.

Both will smoke a bit on startup if choked, it's not just black, it's blue in there.

Goes away instantly when you get out of the choke.

 

[Slick17601]

Originally Posted By: JTK
Is this a vert or horizontal shaft 15hp?

Like said, vertical shaft will often smoke intermittently if you run the 2 full quarts of oil in them. Lowering the level to the midway mark on the dipstick will help if this it the issue.

I wouldn't even consider a tear-down unless it consumed oil like a mofo, or sounded and/or ran like poop.


+1, if it's running well, keep on truckin'