Cub Cadet 2000 series 15 HP Kohler engine.

[Dan Levine]

Issue? I found Gas in the Oil when I went to change the engine oil today. Before, I put the mower away last season. I gave it a oil change & new oil filter. After that, Mower was parked/stored in the shed for 3 months. Here I am, 3 months later. I released the engine oil drain-plug. Oil came-out as thin as water, smelling of gas. I see no signs of gas leak underneath the mower. Didn't smell gas until after I pulled the drain-plug.
Has anyone else had this issue with gas in the oil?
The only way Gas could get into the crank case oil is if the needle valve in the Carburetor is not sealing or needle valve seat isn't sealing. If this is a Carburetor issue, I'm in shocked, gas isn't over-flowing out of the carburetor to the ground. Engine runs great. Fires up on first crank every time. I had no past carburetor issues.
I ended-up installing a in-line fuel shut-off valve to the fuel-line. This way, I'm able to shut-off the fuel when not in use.
With fuel electric Generators and moped/scooters. These are equipped with a automatic vacuum fuel shut-off switch on the fuel tank to avoid this type of issue. These Fuel shut-off switches operates off Vacuum from the engine. When vacuum is detected, opens the fuel valve, no vacuum shut's-off the fuel valve. Beyond me, why Cub-Cadet didn't install this type of switch on their mowers.

 

[mfrade]

And that "system" you like is subject to the same type of failure as the needle and seat in the carb. Any speck of dirt/debris can cause a leak or seepage and gas will flow. I always close the valve under the tank and avoid the issue altogether. just mho.

 

[gary noblit]

I've said a thousand times"if it whirs and churns it wears out" If the tank is under the seat you can still put a shutoff near engine..my 2025 is under the seat...

 

[gary noblit]

Dan, sorry I wasn't thinking right you said you did put in inline shut off...I haven't done it but perhaps an inline elec. solonoid tied to ign. switch would work for all...Many carbs have them on the bottom to close off jet...

 

[lpalma]

It has a fuel pump and it is prolly going bad leaking gas into the crankcase, even when the engine is running thinning your oil till it goes BOOM!