6.5 hp B&S...which oil?

[Greg L]

My wife just bought me a new Craftsman mower, with a 6.5 hp Briggs&Stratton 4-stroke.

Rather than use the stock 30w oil bottle, I decided to break-in the motor with straight 20w Pennzoil and a little SLOB.

Was it ok to do this for now? Should I use the stock oil later, or not worry about it. (Pennzoil was used in my old Techumseh motor & never had problems).


GL

 

[1999nick]

I do not understand why you did not use the 30W oil that came with the mower for the recommended 5 hour break-in. After the 5 hour break-in, B&S's #1 recommendation for ALL temperatures is synthetic 5W30. They even sell this under their own brand name. 30 weight is OK above 40 degrees; they state that if you use a regular multigrade dino such as 10W30, you might experience oil usage.

Isn't SLOB mainly an antiwear additive? Why would you use it during break-in, which is, in essence, a period of desirable wear as the different engine surfaces mate with each other?

 

[Merkava_4]

I agree with everything Nick said. You should've just used the bottle of straight 30 weight and left it at that.

 

[Doc8404]

now he's going to sweat this whole ordeal.

drain whatever you have in it and stick with the 30w....

 

[Gilitar]

Just run straight SLOB.

 

[Bror Jace]

Greg L, it probably wasn't the best thing you could have done but at this point you'll be fine if you merely ran it for a handful hours and can now drain it.

How many hours did you run on straight 20 and SLOB?

Get the mower warmed up, drain it and marvel at the 'silver soup.' Use the straight 30, run [i[that for a few hours then drain it too (again, hot!).

Then switch to something in a 30 weight ... straight 30, XW-30 synthetic, etc ....

 

[jorton]

Will the slob thicken the 20w a little? If so then that was a good idea.

When I tore down my old #@$%! mower motor I was surprised to find no deposits or sludge so I don't think oil additives are needed.

The powerful 6.5 should be very easy on oil.

 

[jorton]

(Oh sorry I used lower case B, S for Briggs & Straton.)

 

[Doc Holiday]

My mowers call for straight 30w motor oil. One of the two says 10w30 can be used for winter, the other say 10w30 is ok but to check the level often if its not synthetic. I've tried both and the conventional 10w30 doesn't fair well in these mowers. So I use 30w. My question is what do you guys think about me running 10w30 high milage in them, since this is a more robust thicker oil than conventional 10w30. Would it fair well against 30w?? Yes I could just use synthetic 10w30 but with no oil filter I don't see the point as I change it often. Thoughts?

 

[MADMIKE]

I prefer the 15w40 HDEO's for my lawn equipment. Better temperature flexibility than the single weights and strong add packs. And most 15w40's actually meet the pumpability requirements of a 10W-40 oil.

 

[SLM]

Run a cheap HD 30, the mower should last a long time.

 

[mazduh30]

I usually just run SAE30. If by chance I don't have SAE30 around when I do my oil change, out comes the 10W30 or 10W40.

 

[Titan]

Delo 15w40. It will last longer than the mower deck and wheels.

 

[Buick92]

I use Supertech 10w30 synthetic from Walmart in my B@S engine, I think it's like 2.97/quart, seems to work well.

 

[Greg L]

UPDATE:

So 3 weeks ago I drained the 20w Pennzoil & switched back to usign the OEM 30w oil from Sears.

After using the engine for about 2 weeks and 2.5 hours of use, the engine seems to be running more roughly than before. I've checked the new oil level & it seems fine.

Time to change out this oil again? Thinking about going back to the single weight Pennz, or trying Rotella 30w....thoughts? Comments/suggestions welcome

GL

 

[kkreit01]

Use what your manual recommends.

 

[Gilitar]

It has a little more drag (load) with the 30w. This will cause the mower to run slightly rougher. This however has NOTHING to do with how well the oil protects. Leave the straight 30 weight in there.

 

[Bill Kapaun]

If the oil is hot, I can't see 30 weight oil making the engine run "rougher" than 20. I would maybe expect the engine to be noisier with the 20.
I used to use 20W-50 or 15w40 in my 18+ year old Honda. After going to 10w30 to make cold weather starting easier, it seemed the thicker oil had made the engine a bit more "sluggish". That was pretty subjective tho-
My first mowing in the Spring tended to be in thick, wet, ankle high grass. Sometimes while it was raining, because I didn't want to wait another week or 2. A situation where the engine is working hard.

 

[Greg L]

FOLLOW-UP:


Ok, so I switched it back to the Sears factory oil that came with the lawnmower about 3 weeks ago. Ran it for about 3 hours over a period 2 weeks worth of mowing, while checking the level frequently.

The problem was that it now began to virbate a little more than usual, as compared to the Pennzoil 20wt. Was noisy also.


So screw it.....at this point I drained the oil again & decided to stick in some 30wt Castrol HD oil that I had bought over the winter. After restarting and running the mower for about 1/2 hour, it quieted down and the vibration was minimized. I'll run this for a while & see how it goes.

But the Sears/Craftsman oil (or whatever it is) will stay out from now on.

GL

 

[marco246]

Well, you've certainly got any break-in metals flushed out of the engine by now. You should be happy with the Castrol, or any brand-name SAE 30 in that mower.