Oil Weight for Kaw FX801V

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Jan 16, 2021
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I have a Kubota zero turn with the Kawasaki fx801v engine on it and this coming year will be its 2nd oil change. I used the OEM stuff last time since it was part of the deal when I bought it. I am exclusively Schaeffers and would like to put some in this one. They discontinued their 10w40 line some time ago and it seems to be what they generally prefer for this engine. However you can go to 20w50 it says in the manual. I am in southeast Ohio and in the spring and fall it can be a little cool so I am not sure if 20w50 would be to thick or not. Am I correct in assuming if you can go clear to 20w50 in these engines 15w40 shouldnt hurt?
 
+1

They recommend 20w50 mainly for commercial use in hot climates. The newer Kawis tend to burn a bit of oil. With that said I would run a 15w40 without hesitation. I usually run that in my Kawasaki powered Exmark mower year round.
makes sense it is a commercial engine and it does use a bit. Nothing crazy but I do see where it would be an issue in a commercial setting where they run them all day every day. Schaeffers makes a 15w40 racing oil that has a good dose of zinc that is probably what ill go with
 
My pick is 5w40 or 0w40 for synthetic or 15w40 for general. Kawasaki sticks with 10w40, because it is what they have and gas engine motor oil are usually 10w40. My Kawasaki FR730 has 5w40 in it.
 
My pick is 5w40 or 0w40 for synthetic or 15w40 for general. Kawasaki sticks with 10w40, because it is what they have and gas engine motor oil are usually 10w40. My Kawasaki FR730 has 5w40 in it.
This. (y) They will all work very well.
 
I have used both 10w40 and 15w50 in mine and just stuck with 15w50 since that's what my Briggs takes and to just keep one oil. Kawasaki manual shows 20w50 good to 32 degrees and 15w50 good to around 20 degrees.
 
I’ve used Rotella 15w40 T5 in my 1998 liquid cooled Kawasaki 501V for a couple of decades. I replaced a valve cover gasket several years ago and the rocker arms and valve springs looked new and it uses no oil and still runs great.
 
I was at Kawasaki school today. Part of the training.
20250204_171918.webp
 
I was at Kawasaki school today. Part of the training.
View attachment 262107
They missed the part on teaching image rotation, my neck is hating me for being lazy and not turning the image over myself. Half joking, this is great information.

There is a lot of very unscientific "I've used 5w-30 for years and my motor has run for XXXX long" and similar posts floating around the web regarding these engines. When I bought my Kawasaki engine last year (attached to a $8K machine), naturally I did a fair bit of research and came across what's essentially a TSB for dealers with Kawasaki updating their oil recommendations to include, and even recommend 20w-50. This occured a few years ago and the engine design hasn't really changed since.

After a short break in period (5 hours or so) I wasted no time switching to a 15w-50 HDEO as I was in the thick of summer by that point. Using an IR heat gun, this engine gets HOT. I have a hunch some of it is emissions driven / EPA regs, perhaps just the engine design.

We get cool spring / fall temps here, so I've settled on Motorcraft 15w-40, that variety that has the ford spec which eschews the latest CK-4 or whichever recent spec that limits phosphorus. I don't like the price though. I recently picked up a ton of Chevron Delo 5w-40 synthetic on clearance, I have no qualms about using that after the Motorcraft. Definitely won't be running 10w-30 or anything lighter.
 
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