What oil to use in an older 12 hp Kohler K301 S engine?

[peterclement]

Hello,
I've just purchased a 5665 model Gravely walk-behind tractor, 1984 year. 12 hp Kohler K 301 S engine, single cylinder gas.
I would like advice on the best oil to use. No oil filter on this older engine. Air cooled.
Original manual says 30W above freezing, 10-30 below freezing, and an SG or SH classification, which are now obsolete.
Should I stay with those weights? I will change religiously at 25 hours maximum.
Any advice on the best brand, whether regular or synthetic, etc.

Thank you so much for your help, Peter

 

[JavierH19]

At 25 hour intervals you're doing good. I use whatever cheapest HDEO oil i have on hand but i used to use regular 30 grade oils and those give no issue. Currently using supertech 15w-40. I have an 06 gravley zero turn with a 23hp kohler engine and an 07 deere with a 21 hp briggs. Not only is 15w-40 plenty thin for a mower at 20f but i don't know anyone who mows in temps below 60f anyway.

 

[skyactiv]

If you happen to see 10W30 diesel oil at a Walmart, I recommend that. Chevron Delo, Shell Rotella, doesn't matter.

 

[zrxkawboy]

I would stick with the recommended viscosities.

 

[Brian123]

Hello,
I've just purchased a 5665 model Gravely walk-behind tractor, 1984 year. 12 hp Kohler K 301 S engine, single cylinder gas.
I would like advice on the best oil to use. No oil filter on this older engine. Air cooled.
Original manual says 30W above freezing, 10-30 below freezing, and an SG or SH classification, which are now obsolete.
Should I stay with those weights? I will change religiously at 25 hours maximum.
Any advice on the best brand, whether regular or synthetic, etc.

Thank you so much for your help, Peter

Amsoil Small Engine 10W-30 or 10W-40

 

[Soft Cars]

I'd try to find some 10W-40 Mobil Super if it was me.

 

[mattwithcats]

Shell Rotella T4 conventional or T5 semi synthetic in 10W-30…

 

[joegreen]

I have a 77 john deere 212 with the k301. Also calls for 30wt. I would stick with that as multi grade has a tendency to shear and also use more oil while operating. But really these engines will run just fine on whatever. Here was my post asking about oil. https://bobistheoilguy.com/forums/threads/what-oil-for-1977-12hp-kohler-k301.364079/#post-6350725

 

[Lubener]

Hello,
I've just purchased a 5665 model Gravely walk-behind tractor, 1984 year. 12 hp Kohler K 301 S engine, single cylinder gas.
I would like advice on the best oil to use. No oil filter on this older engine. Air cooled.
Original manual says 30W above freezing, 10-30 below freezing, and an SG or SH classification, which are now obsolete.
Should I stay with those weights? I will change religiously at 25 hours maximum.
Any advice on the best brand, whether regular or synthetic, etc.

Thank you so much for your help, Peter

I would use any name brand SAE 30. Not a big deal.

 

[ka9mnx]

I use SuperTech 10w-40 SP in all my OPE. It used to be plentiful and cheap but my WM doesn't seem to stock it now. Glad I stocked up when I did.

 

[Fordiesel69]

I have a whole collection of Kohler K Series and Magnums.

Please keep in mind that these were most likely operated back in the day with non detergent oils, and / or operated with very few oil changes (owner negligence). What I find is that when us that are in the know do our research and select a quality modern oil, we un-intentionally disrupt all the iron and sludge deposits, wearing the engine out faster than normal. There is no oil filtration or factory magnets in these.

What I have done and it seems to solve the problem, is life the engine off its oil pan and solvent clean the entire crankcase, and also solvent clean the oil pan spotless. Then stick with a modern oil and add a magnetic drain plug, or put a strong one on the outside of the engine in a low area. Limit the oil changes to a max of 25 hours.

These have the most wear on the crank pin, and cylinder wall.

5w-40 diesel, 10w-30, 15w-40, 10w-40, and SAE 30 are all good choices. I like diesel rated oils best.

 

[Chris142]

I would use any name brand SAE 30.

That would be my choice

 

[Revving2Redline]

HPL,REDLINE or Amsoil !!! Just kidding, but I'm sure someone is trying to get maximum horsepower from their OPE lol.

 

[JTK]

I ran 15w40 in my Kohler K's.

Kohler always recommended SAE30 for the K-series.

Main thing is keeping the level full and changing it.

 

[Joel_MD]

I had a 1971 John Deere Model 120 "patio tractor" for many years. It had a K301. What a fantastic engine! I always used 30 weight oil. The few times I used it in the winter I would preheat the engine with a portable heater for a couple of hours so the oil wouldn't be so thick.

If I had that same tractor now I would probably use a HDEO 15W-40 such as Shell Rotella or Mobil Delvac.

 

[jeepman3071]

I have a 1968 Gravely Commercial 10A with a 10hp Kohler. I run Napa or Rotella 15w40 in both the engine and transmission.

 

[repairman54]

Summer use, at least straight 30 in a certified oil, not a ''qualified'' oil.

 

[Cujet]

Mobil 1, 15W-50 is ideal if you are not using the engine in cold weather.

 

[tnt_motorsports]

I run Farm & Fleet 5w40 HDEO in my 15hp Kohler engine that’s in my Deere LT150. It started right up tonight when I needed to blow snow and runs great in the summer at 90+F. I would not hesitate to put a 5w40 HDEO in your engine.

Just my $0.02

 

[MolaKule]

I had Kohlers on my Riding Mower/Garden Tractor and Wood splitter back in Kansas.

I used synthetic 30 grade all year round.