Briggs and Stratton Engine Oil

Sep 17, 2012
A Barrier Island
Just bought a new Craftsman self-propelled mower. Has a 150cc B&S engine. I filled it with the oil provided, 15 ounces. It is a straight 30W. The bottle has no specs other than it is approved by B&S and is for use from 40-100F temps.


1. Who makes this oil?
2. Any break in precautions? The mower runs wide open.
3. How many hours until a change.
4. What should I use then?

My observations,

1. B&S engines are stout units. Current mower 190cc model has at least 300 hours and other than hard starting is a beast.
2. The old model was a TroyBuilt. New one as mentioned Craftsman. They look remarkably the same.
3. Mower engines generally are great, the rest of the deck, cables need improving.

My opinion is that any name brand 30wt oil will do just fine. If you don't mind cost Amsoil makes a small engine oil. If possible i would change the oil at 5 hours of use. Install the oil of your choice and change it at the interval shown in you user manual.
You might want to double check the fluid capacity in the owner's manual; sometimes they don't give you enough oil.

Their synth works great too:

I change my mower oils after their 1st run, and then yearly.

I am not a fan of BS plastic carbs or fuel lines that don't have a filter. If not equipped, install one from your local autopart, hardware, or small engine shop.

I am not a fan of BS plastic carbs or fuel lines that don't have a filter. If not equipped, install one from your local autopart, hardware, or small engine shop.
on my new "yard force" the fuel line is about 4" long including the ends that slide over the nipples.
nearly impossible to put anything besides the tiniest screen filter... ie not a real fuel filter.
The tank however does have a mesh strainer at least as good as that 150 micron screen you linked.
It has the 6.75 briggs.
The carb died over the winter (sat 2-3 months)
went from starting on 1-2 pulls to nothing.
10.99 ebay carb fixed it.

Replacing the fuel line was harder than the carb. I was out of replacement fuel line (had to cut it off the tank)
So I used some tygon fuel line but its OD is smaller ... normal spring clamps dont fit.
I wish that my Toro's had a mesh screen in the tank. Last carb clean out had dead grass bits. Had to remove mowing permission from the ol' lady. She wouldn't dust off the fuel cap prior to refilling.
All lawnmowers are designed to run wide open, all of the time. It helps cooling and doesn't hurt a thing.
I researched breaking in small engines on a gocart forum a while back. They recomended oil change after 1 hour, then again after 1 hour, then run normal OCI. I did so on my new generator, and the first 1 hour oil change was full of metal shavings and somewhat milky as well - likely assembly lube. Remember there is no oil filter so the only way the break in metal parts get out of the crankcase is to drain it.
Most cheap lawn mowers are made by MTD, no matter what brand name you bought it under :sneaky:

Also, the cheap Dollar Tree oil works great in them. It is a 10w30 synthetic blend.
I change after the initial mow. Then yearly. Have always used BS straight 30 with one oz MMO halfway through summer. Little bit of MMO in the fuel or a quarter bottle of gumout if I remember to save some every so often. Sta-bil seems to find its way in there also. Change plug yearly and take a peek at the air filter. Every so often take some oil you have laying around and blot a rag and coat the bottom of the deck. I have been lazy and have just been buying replacement blades. But if your going to sharpen.. put a nail on a board and balance the blade. Have a beer or two during the mowing, trimming, etc... while I listen to the local HAM radio... BBQ and maybe another beer or 4... my favorite day!