B&S V-Twin 725cc oil question

Joined
Nov 22, 2004
Messages
8,762
Location
Texas
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.
 
Joined
Apr 15, 2010
Messages
6,762
Location
Connecticut
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.
 
Joined
Jan 22, 2011
Messages
6,025
Location
Ohio
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.
 
Last edited:
Joined
Jan 22, 2011
Messages
6,025
Location
Ohio
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.
 
Last edited:
Joined
Dec 7, 2003
Messages
11,591
Location
Florida, Cape Coral
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
 

4WD

Joined
Sep 21, 2010
Messages
18,485
Location
Texas
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 …
 
Joined
May 17, 2006
Messages
4,394
Location
Central Wisconsin
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¢
 

GMBoy

Thread starter
Joined
Nov 22, 2004
Messages
8,762
Location
Texas
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

Thread starter
Joined
Nov 22, 2004
Messages
8,762
Location
Texas
Thanks for the helpful feedback from most of you. I plan on running that oil for the 50 hr interval.
 
Joined
Jan 9, 2008
Messages
648
Location
WV
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.
 
Last edited:

GMBoy

Thread starter
Joined
Nov 22, 2004
Messages
8,762
Location
Texas
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.
 
Top