Hello,I need a little more information from you. Have you verified that it is gas in the oil by pulling the fill cap and smelling it for a gas smell or changing the oil and checking that? If it were coolant in the crankcase your oil would foam white. Did your dealer take a fuel system pressure reading and inspect the injectors, or did they just replace the parts?It is very difficult to get gas into the crankcase on a FI system being it would have to pass through the injectors and into the top end first. This will cause poor running and smoke. It will also wash down the cylinder walls causing hard starting and lower compression readings. Here is what I would check. First, you need to know your pressure readings. You may wish to do this yourself unless the dealer recorded the readings for you. The gas not injected into the motor is returned to the tank. Verify the line is clear by removing it from the rail and opening the gas cap. Supply low air pressure to verify the line is open to the tank. Next, open up the air filter housing. There is a curved hose in the top. This is the crankcase vent. Make sure this hose isn't damaged or missing. It may be possible for the crankcase vent to draw some of the air/fuel mixture back into the crankcase if there is a problem there. Your compression readings should be a minimum of 170psi. That is with the spark plugs removed and engine cranking at 250rpm. Oil pressure should be 40psi while running. Check those things and let me know what you find. Any additional information or issues you have noticed would be helpful. Doug
Clearly the dealer you took the tractor to didn't have a handle on the problem. That happens. I was a mechanic and service manager for over 20 years and when I messed up, or one of the guys messed up, we made it right. I would speak directly to the owner and calmly explain that you have had to diagnose the problem on your own, been unable to fully use the machine all summer and you spent a good deal of money on parts you didn't need. Add that you are a local business owner and would like to see them put this right for you. If that doesn't work, I'm happy to keep working with you until the problem is fixed. That's what I do. You are welcome to toss in a bonus at the end if you wish. I have a link to the engine manual. The photos aren't good but the diagrams and text are ok. I also have the Clymer manual. The hose routing is on page 11 of that manual. See if that matches your return line layout.
Engine parts can be purchased through JD or through any Kawasaki small engine seller online. If your dealer isn't willing to go good on some of the repair costs, I wouldn't be buying parts from them. Doug
I've only seen one bad Kawasaki head in 30 years so chances are it's just a gasket leak. But always check the mating surfaces to verify they are perfectly level.
Let me know if you need more help. If not, please click on the accept button so I get credited for my work. If you don't do that then I get nothing for the time I have spent. Thanks. Doug