oil weight for a new B&S mower engine

[dkcase]

OK...
New lawn mower 6.75 HP Briggs.

On the way home I mentioned to my wife, "You won't believe me, but I don't have the right oil."
I had looked at the owner's manual on-line before purchase--Sears. It calls for SAE 30 over 32degrees F.

I DO have other weights -- 5W30, 10W30, 5W40, 15W40, and 20W50.

It said if you use a multi-weight oil, expect oil consumption.
Turns out it came with some oil for the first fill, and I used that.

I don't mind getting some new oil for it in 30, but does anyone really think it will matter much ?

Pre-BITOG, I would have put in what I have and not worried. OR-- Gotten the SAE 30, and not assumed that I know anything.

My old mower, Briggs engine, just crapped out and won't stay running. Before the last couple uses, it hadn't so much as hiccuped since 1979. I think it needs valves, compression is low. New engine or short block just didn't look as good as a new one economically.

 

[BigDenCCMD]

Use synthetic 10w30. I bet the owner's manual reads that that is fine in just about any temperature.

 

[55Test]

Maybe the carby on the old mower is plugged up with dirt? In my experiences with old mowers, they start running bad long before they die out completely. Burning oil, running excessively rich, inconsistent idle, hard starting, etc. I've seen some mowers do that for years and they keep going.

 

[N2OIL]

Use the 30Wt as break in oil. Then switch to brand X 5/30 or 10/30 on your next oil change. I have yet to see any oil consumption issues on any outdoor power equipment used in this manner. The time given is 5 hours on break-in oil. This process worked well for Honda push mowers all the way up to our John Deere lawn tractor it had a 24HP v-twin engine. The oil used was a 10/30.

 

[lobo11]

I use straight weight oils in small engines used in the summer months, the only small engine I run a multi-weight in is my snowblower, and that is synthetic.

 

[obbop]

I am lazy. And, I always had trouble determining what the oil level on the dipstick is when replacing the oled oil with new.

I suppose I could obtain a graduated measuring device to ensure I input the correct amount of new oil but..... see the first declarative utterance in the first paragraph.

So..... to ease my pain, to simplify my life, to ensure the proper amount of oil is shoved inside the engine.......... I buy the straight-weight 30W oil in the proper-sized container. The manufacturer offers it and so does Ace hardware.

No fuss, no muss (what's a muss?) no wracking my brain trying to add the proper amount of slippery stuff to keep the engine innards moving. Nope, not for me. Just dump and go.

 

[MolaKule]

A good synthetic 10W30 is best and most engines today use between 20 and 24 ounces or 0.660 Liters or 0.7 quarts.

 

[penzdude]

i use the clear dollar store tupperware type containers that go up a qt, shown in ounces for the lawn stuff. i use amsoil 10w30 in my mower, a honda ohv harmony, but the stock of your 15-40 would be a good alternative. penz

 

[Islandvic]

I have M1 10-30 in my 15 year old B&S 3.5 HP Murray mower.

Only a slight puff of smoke at startup.

Break in the mower for 5hrs, change it with the 10-30 on hand, and check oil level after each use.

If it consumes, drain and refill with the 15-40 you have on hand.

If it consumes again, go 30HD.

 

[road_rascal]

I'm using Mobil 1 5w/30 in both my mower and snowblower. Wait a minute- they're Tecumseh engines- never mind...

 

[Blue99]

If you already have 10W-30 & 15W-40 on the shelf, I'd run a 50-50 mix to achieve a 12-13 cSt brew with slightly higher ZDDP levels than available in most SL/SM multi-viscosity oils.

On a side note, whenever I change the oil in my B&S powered push mower, the story of a Briggs engine running on no oil, comes to mind.

This is part of the Snake Oil article from Road Rider magazine that appears several places on the internet. Here's a Link to the Article at 3MP's Paradise Garage website.

The Infamous "No Oil" Demo
At at least three major motorcycle rallies this past year, we have witnessed live demonstrations put on to demonstrate the effectiveness of certain oil additives. The demonstrators would have a bench-mounted engine which they would fill with oil and a prescribed dose of their "miracle additive." After running the engine for a while they would stop it, drain out the oil and start it up again. Instant magic! The engine would run perfectly well for hours on end, seemingly proving the effectiveness of the additive which had supposedly "coated" the inside of the engine so well it didn't even need the oil to run. In one case, we saw this done with an actual motorcycle, which would be ridden around the parking lot after having its oil drained. A pretty convincing demonstration -- until you know the facts.

Since some of these demonstrations were conducted using Briggs and Stratton engines, the Briggs and Stratton Company itself decided to run a similar, but somewhat more scientific, experiment. Taking two brand-new, identical engines straight off their assembly line, they set them up for bench-testing. The only difference was that one had the special additive included with its oil and the other did not. Both were operated for 20 hours before being shut down and having the oil drained from them. Then both were started up again and allowed to run for another 20 straight hours. Neither engine seemed to have any problem performing this "minor miracle."

After the second 20-hour run, both engines were completely torn down and inspected by the company's engineers. What they found was that both engines suffered from scored crankpin bearings, but the engine treated with the additive also suffered from heavy cylinder bore damage that was not evident on the untreated engine.

And Kids, don't try this experiment at home!

 

[MN Driver]

I've also been surprised at some engines running without oil. I have seen people who totalled their cars and decided to drain the oil out of the engine and run it until they wouldn't anymore. You wouldn't think that it would take 12 minutes before an idling car engine with over 200,000 miles would seize, but the video showed it being done. After about 2 minutes into the video the radiator pipes burst shooting steam everywhere from overheating internally, so it seems that the final strokes of the engine were probably of the whole thing melting together.

 

[1999nick]

quote:

---

Originally posted by dkcase:
OK...
New lawn mower 6.75 HP Briggs.

On the way home I mentioned to my wife, "You won't believe me, but I don't have the right oil."
I had looked at the owner's manual on-line before purchase--Sears. It calls for SAE 30 over 32degrees F.

I DO have other weights -- 5W30, 10W30, 5W40, 15W40, and 20W50.

It said if you use a multi-weight oil, expect oil consumption.
Turns out it came with some oil for the first fill, and I used that.

I don't mind getting some new oil for it in 30, but does anyone really think it will matter much ?

Pre-BITOG, I would have put in what I have and not worried. OR-- Gotten the SAE 30, and not assumed that I know anything.

My old mower, Briggs engine, just crapped out and won't stay running. Before the last couple uses, it hadn't so much as hiccuped since 1979. I think it needs valves, compression is low. New engine or short block just didn't look as good as a new one economically.

---

Briggs and Stratton recommend the use of multigrade synthetic motor oil in 5w30 and 10w30 weights. They do not recommend the use of dino multigrades, as they say this causes consumption. They sell a synthetic 5w30 under their own brand name. They recommend these synthetics at all temperatures.

 

[Hokiefyd]

In most any engine, the lubrication load at idle is incredibly low. Most modern automotive engines run with as little as 4-5 psi of oil pressure at idle (it surprised me when I learned that!). I would expect any modern oil to leave some type of film on the bearing or journal surfaces to enable it to run at low/no pressure for a while under no load. Our small engines aren't pressure-lubed anyway, so it probably doesn't take much of a film to properly protect them. I must say that it's impressive for one to run for 20 hours with no oil! I bet it's coincidence that the one with the additive had the damage. Both engines had crankshaft/pin damage, and I'm sure the chips/particles from that damage happened to get into the cylinder of the treated engine (to cause the damage) and maybe didn't happen to get there in the non-coated engine?