B&S V-Twin 725cc oil question

[GMBoy]

Got an older Craftsman lawn tractor that has had a diet of 10w/30 mobil 1 changed at 40-50hr intervals. It is the V Twin 725cc engine - good engine for sure! Anyhow, my son thought he heard rod knock and was worried. I listened and heard it too - it was bad so we did a quick oil change and this time put in Mobil 1 V-Twin 20w/50 that I use on the Harleys . Rod knock was still there - but it turned out to be the steering linkage loose and hitting the crank pulley making the noise.... So we are actually ok thank goodness! With that - would you guys leave the 20w/50 in there? I personally think it will be ok especially in Texas but I also know 10W/30 is the recommended oil.

 

[tomcat27]

I used to run 30w in mine

 

[jeepman3071]

20w50 won't hurt anything especially in Texas. Once it gets a bit cooler you might want to switch to the 10w30, but no sense in wasting good oil.

 

[Lubener]

I would not run 10w-30 in my rider. Mine only gets straight 30 or 20w-50 for summer use. Has worked for me with Ohio's temperatures and I don't see the heat as you do in Texas.

 

[Slick17601]

Mobil 1 10W-30 High Mileage is a solid choice for small engines.

 

[Lubener]

Originally Posted by Slick17601
Mobil 1 10W-30 High Mileage is a solid choice for small engines.

For that older B & S, I will bet in the manual that SAE30 is the preferred weight to use, not 10w-30.

 

[Eddie]

I run 10w30 T5 synthetic blend in my B&S 20HP twin here in FL. But, 20-50 will do just as well in the summer heat in my opinion. I would go back to a synthetic 10w30 at the next scheduled oil change though. Ed

 

[philipp10]

so you thought you had a rod knock and changed the oil? What did you think a thicker oil was going to do......???

 

[4WD]

Yeah … air cooled and all … just be careful that it might pop a wheelie on ya now … ...·

FWIW: Just put Delvac 15w40 in my 19 HP Briggs and it's never run better …

 

[dwendt44]

The lawn mowers and tractors we see here are all air cooled and oil temperatures can and
often do get up to the 250° and higher in the summer, especially in the southern tier of states.
Many commercial users go with a 15W-40 oil.

My 2¢

 

[CT8]

20W-50 works great in air cooled engines.

 

[thastinger]

I run Mobil 1 Euro 0-40 in my 27HP B&S and my 17HP Kawasaki mower engines

 

[GMBoy]

Originally Posted by philipp10
so you thought you had a rod knock and changed the oil? What did you think a thicker oil was going to do......???


Thicker oil can lessen the noise.

I really was draining the oil looking for metal - there was none.

 

[GMBoy]

Thanks for the helpful feedback from most of you. I plan on running that oil for the 50 hr interval.

 

[bchannell]

I had a 27hp Briggs in my "extra" tractor a while back and used M1HM 10w30 and it seemed like a great choice. I think those bigger engines like some sort of 30wt oil whether it be straight 30 or multi vis.
In modern OPE engines, I don't think you'd ever go too far wrong using a good HD 10w30 oil. Is it the best you could ever use, probably not, but I'm betting you'd never know the difference in this lifetime.

 

[GMBoy]

Originally Posted by bchannell
I had a 27hp Briggs in my "extra" tractor a while back and used M1HM 10w30 and it seemed like a great choice. I think those bigger engines like some sort of 30wt oil whether it be straight 30 or multi vis.
In modern OPE engines, I don't think you'd ever go too far wrong using a good HD 10w30 oil. Is it the best you could ever use, probably not, but I'm betting you'd never know the difference in this lifetime.



This is my extra mower as well, lol. My normal oil is 5W/30 or 10w/30 M1. I agree with you.