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I have a 15 year old Ferris IS1500z mower with the Kawasaki FH641V-BS25-R engine. The engine has 986 hours on it and developed multiple oil leaks early this season. I replaced the upper seal, lower seal, governor shaft seal and installed the new breather kit which contained the cover, new improved gasket and breather valve. After assembly the engine started quickly and ran fine, most importantly no oil leaks. Over the course of a couple of weeks I put 6 + hours on the mower with no issues. Then after the mower was parked for several days when I tried to start it gray/white smoke poured out and it wouldn't stay running. When I removed the valve covers to see if I had a valve issue, I had a mixture of mostly gas with some oil pour out of both cyl heads. I would estimate 4 to 6 ounces in each. The rocker arms and pushrods all seem fine. Any help with this issue will be greatly appreciated. Also if anyone has a recommendation on an engine replacement, Kawasaki, Briggs or Kohler that will work in the IS1500z it would also be appreciated. Thanks in advance.

Gas typically enters the engine oil because the fuel tank is mounted ABOVE the carb. In these instances, GRAVITY is constantly pushing fuel against the float valve inside the float bowl. When any issues (wear, grit, etc.) adversely effect the float valve, fuel will flow down the intake, past the intake valve, and past the piston rings.

Because of this, lots of modern lawn care equipment is now fitted with an "automatic" fuel cut off valve. These fail all the time. And when they do, you have no warning until fuel enters the engine oil. I highly suggest you cut the fuel line and add a manual fuel shut off valve. That will permanently end this problem. They cost well under $7 and take a whopping 2 minutes to install. Click to see... Manual Fuel Valve

The float valve has most likely failed and has overfilled the carb, and it has ran down into the intake into the cyinders where it seeps past the rings into the oil. Or the gas could also get into the crankcase tnrough the breather depending on location. You will need to remove and clean the carb, and at a minimum replace the float valve and the bowl gaskets. Also while you have it apart shake the float to make sure there isn't gas inside of the float. Then change the engine oil and filter if it has one due to gas contamination.

Shut off valves are fine for setting to help prevent oil contamination but really should fix the initial problem instead of just trying to bandaid the issue. as suggested by Born2Mow.

I agree 100% with IL on not going the band aid repair. Time to solve the problem with a carb rebuild. Many DYI guys try to save a few pennies, but down the road find out it would have been cheaper to fix the problem right the first time. Us old farts learned this the hard way years ago, learn from our mistakes.

Float valve : Kawasaki 16030-7004

Born2Mow said:

Gas typically enters the engine oil because the fuel tank is mounted ABOVE the carb. In these instances, GRAVITY is constantly pushing fuel against the float valve inside the float bowl. When any issues (wear, grit, etc.) adversely effect the float valve, fuel will flow down the intake, past the intake valve, and past the piston rings.

Because of this, lots of modern lawn care equipment is now fitted with an "automatic" fuel cut off valve. These fail all the time. And when they do, you have no warning until fuel enters the engine oil. I highly suggest you cut the fuel line and add a manual fuel shut off valve. That will permanently end this problem. They cost well under $7 and take a whopping 2 minutes to install. Click to see... Manual Fuel Valve

Click to expand...

I'll pick up a manual cut off valve in the morning & install it before I take off the carb and clean it up good & check the internal float valve. This engine has the fuel cut off solenoid at the bast of the float bowl so I plan to replace that also. Thanks to everyone for the great advice. I'll post the results of my efforts hopefully by tomorrow afternoon.

I always fit an in line tap to every mower I service.
Lots of people never bother to use them but I fit them just the same.
If for no other reason it makes it easier for me to replace the filter or remove the carburettor.
Honda fit them to most of their carburettors, every locally made push mower down here had a fuel tap as part of the fuel outlet from the fuel tank from 1952 .
And now days when carbs vent into the engine so you can not see or smell the leaking fuel, a shut off valve is even more important .
And the side benefit is shutting the fuel off and starving the engine off will always leave the plug very clean which aids cold starting .

However their job is not to circumvent a failed float valve in service .
Unless it is working properly the engine will be running rich so float valves need to be there and be in proper working order.
So I will join in the chorus
Pull the bloody carb off & clean it it can be a sign of more serious problems like fuel line collapsing .
When you are done, tip the carb & try to blow through the fuel inlet.
If you can then the valve is not working .

I am not sure what Born2mow is talking about but if he is referring to the fuel solenoid on the carb then he is wrong all that does is block off the main jet to prevent unburned fuel passing through the engine during shut down.

fgsiii said:

I'll pick up a manual cut off valve in the morning & install it before I take off the carb and clean it up good & check the internal float valve. This engine has the fuel cut off solenoid at the bast of the float bowl so I plan to replace that also. Thanks to everyone for the great advice. I'll post the results of my efforts hopefully by tomorrow afternoon.

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no need for a new 21188-7003 Solenoid, that's not what caused your problem, put that $90 back in your bank account.

fgsiii said:

I'll pick up a manual cut off valve in the morning & install it before I take off the carb and clean it up good & check the internal float valve. This engine has the fuel cut off solenoid at the bast of the float bowl so I plan to replace that also. Thanks to everyone for the great advice. I'll post the results of my efforts hopefully by tomorrow afternoon.

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Leave that bloody solenoid alone.
It does nothing beneficial for the engine & is a lump of very expensive useless EPA required junk
When the carb is apart check that it retracts when the key is in the on position .
If you think I am talking rubbish then take the carb off and try to blow through the fuel inlet
You will see there is nothing preventing your lungs blowing air through the carb so there is also nothing stopping fuel flowitng through it either.

bertsmobile1 said:

Leave that bloody solenoid alone.
It does nothing beneficial for the engine & is a lump of very expensive useless EPA required junk
When the carb is apart check that it retracts when the key is in the on position .
If you think I am talking rubbish then take the carb off and try to blow through the fuel inlet
You will see there is nothing preventing your lungs blowing air through the carb so there is also nothing stopping fuel flowitng through it either.

Click to expand...

Well I love to save money bertsmobile 1 so I will take your advice and not replace it, we'll see what happens tomorrow. Thanks

If the mower has been sitting for a long time they can & do gum up
So you give them a shot of any solvent cleaner you have then work the plunger up & down to clean the gum out
Can take a while but as you have found out they are not cheap.
This itself is price gouging, the actual cost would be lucky to run to $ 10 but because they are a compulsory EPA requirement there is no limit to how much can be charged for them.

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