OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Using Old 20/20w Oil in Briggs.

I want to get on with trying to get this SupesSwift going and I have little experience working of four stroke mower engines. I found the oil was very low but don't want to commit my expensive new four stroke 30 weight oil on it while testing. I was going to just pour in some motor car oil and replace it later but remembered an old Ampol tin I found had single weight oil still in it so decided to just pour that. After emptying the contents, the level was right on max. Will this be ok to run indefinitely or should I replace it when I get it running? The oil is older than the engine!! Much older, but looked good as I poured it through the white funnel.

That will be good MF. If it runs well, I like to run them and warm up the oli and tip it over to drain it.
speedy

I tend to get the cheapest motor oil at repco or autobarn when it comes on special - Nulon 15w40 last time, Gulf Western before that. 5L for $10

If the oil in them isn't disgusting, I will get it going and run for 5 mins, drop the old oil, add 600ml of new, then use it and possibly drop it again.

It all depends on how neglected it previously was.

Often, if it gets replaced again, 15w40 or 10w30 (castrol magnatec or ultraclean) goes back in - I don't usually use sae30

My grandfather has run 15w40 Shell or Castrol in his mowers for years and he bought a Masport with xm50 quantum in 1999, and it runs as good as the day it came out of the factory (doesn't see much use now though)

If you asked me if I would put cheap oil in a commercial Honda I would say no but as we are talking about Briggs, anything goes.

Even olive oil? Extra virgin of course lol.

Whatever rocks your boat MF, after all they are only Briggs. I did try peanut oil in a Chev many years ago, smelt great but didn't last too long

I have had the Nulon (which actually seems to be a pretty good oil) in a GXV120, but have only used it for somewhere near an hour. It will be drained before I next use it.

But if a briggs can run 200ml of black tar, it will love any oil it gets

After a couple of years sitting in the pile after it wouldn't start after getting it home, I pulled it out after recently finding a catcher for it.
I found the air filter foam was putrid with gunk, so replaced it with an old cleaning sponge with a hole cut in the middle and alas it started right up. I was happy to have a working four stroke again after a few years. With the lawn we have, a 3hp Briggs is all the power we need. The SupaSwift is a good chassis.
I fitted a pair of Victa blades (thanks to information on here) and tested it on a patch of weeds and cut beautiful.
I now have found a use for some surplus 15W40 engine oil when I drain the sump.

Good to hear its going well MF

I bought a chunk of foam from clark rubber - I use it for everything from trimmer filters, briggs filters and the victa round 'pre-filter' seal that goes under the paper one.
10 minutes with scissors & stanley trimmer usually yields a good result. I put some Aldi chain bar oil on the filter and squeeze it through - its blue so I can see missed spots and doesn't run/drain off like 15w40.

If the old filter is just really filthy, put on some thick rubber gloves and get seriously hot water with some morning fresh washing liquid and squeeze it through (squirt stubborn spots with SCA degreaser) and then rinse in cold water and air dry - normally cleans well for me. But if the foam is disintegrating, there is no hope

As a note, the old small engine gregory's manual recommends that below 10 degrees, 10w30 'diluted with 10% kerosene' be used in briggs - I have never seen it anywhere since

Tyler, do you know how much to put in and will a 1&1/2" deep rectangle takeaway food container take up the old oil?
Where can I get a front axle retaining clip. One is missing but mower is useable.

Hi MF, Just make one of those wire clips. I make Victa ones, or just do a loop with wire.
cheers
speedy

Hi Speedy,

Thanks man, I'll see how well I can bend up some coat hanger wire. These old flat head Briggs' are quite adorable.

Cable ties must be really good I see it all the time

I think I'll do that for the time being Norm. I thought you didn't believe in that though. I actually considered that earlier but remembered what you said on the matter of using cable ties on mowers -against your ideology or something LOL.

MF, cable ties have their place on mowers around the throttle cable on 4 strokes and around the carby throat on the Briggs carbys but that is about it. I didn't say I would use them to hold the axle in place but I often come across that as a bodge up fix by unknown people, or the old coathanger wire bodge.

NK, the zip tie bodge is a lot easier in this case and will do the same job until I get hold of an original made from spring steel.
Just changed the oil. Wow it was almost line Tyler described. Very black. It will certainly welcome the Shell Helix 15w40 I just poured in.
Mowed the yard with it today. Fantastic old bomb.

Sorry for not responding MF, have had a bad bout of gastro since 11pm monday

I use a 1Litre yoghurt container to drain the oil - 600ml is the general capacity

The air filter should only need about 50ml of bar oil to be fully oiled

It will certainly love the helix

I mowed the front today with the new oil and it performed its task without complaint. I managed to fit a Victa axle retaining clip to the front axle and made up a shim from a piece of scrap tin as non of the Victa ones would fit. It looks to be effective enough.
See pics below.

Hi Tyler,
I forgot to ask, what's the benefit of squeezing oil through the foam? I recall my Ryobi lawn hornets said to do the same. Is it to prevent fine dust from sneaking through the sides?

MF, Adding oil to the air filter makes the foam much more efficient - according to the old gregory's manual it improves the foam filters efficiency significantly (they gave percentages but I can't recall or find them now).

Without the oil, they tend to let the dirt a fair way further into the filter and you can see some dirt in the carby throat. That being said, the issue with oiling them with regular oil I have found is that the oil runs down over a few weeks. Then the base of the air filter ends up covered in oil and gets clogged with a thick 'sheet' of dirt right at the base of the air filter - then the engine runs rich and buggers up the bore through running too rich because no one ever checks the filter.

The chain oil is quite tacky - and sticks in the filter once you massage it through. It does still run a tiny bit, but no where near as bad. You can get specific air filter oils like Fab1 by Maxima (which is actually for bikes), but its a pain to clean.


https://www.briggsandstratton.com/n...-in-your-briggs-and-stratton-engine.html

Thanks Tyler. That link was informative but replace every three months? I don't think so Tim!

G'day MF,
An old B&S Service Manual I have says to wash and re-oil foam filters every 3 months or 25 hours run-time, whichever occurs first. With the proviso that "Capacity of “Oil-Foam” air cleaner is adequate for a full season’s use, without cleaning, in average homeowner’s lawn mower
service. (Clean every few hours under extremely dusty conditions.)"

BTW, this B&S how-to does mention servicing of foam filters, but doesn't say how to do it; https://www.briggsandstratton.com/n...se/how-to-replace-a-foam-air-filter.html

For a commercial workshop, I'd say replacement with a new element would work out cheaper, with their labour rates! And most mower owners don't really want to know about dirty jobs like cleaning air filters.

To elaborate on what Tyler has said, the oil gives the foam the ability to trap fine dirt particles, which dry foam can't do.

There are quite a few tacky foam filter oils on the market, as most off-road motorbikes have this type of filter. There are even water-soluble types available, which saves having to use mineral turps to wash the dirt out with.

G'day Gadge,
where can you normally get these specialist foam filter element oils? Mower shops, auto parts stores and motorcycle accessory shops?
This water soluble version costs three times more yes?
In that case (or something like it), I'll go for chain bar oil.

MF, at Sca or Repco you are generally looking at $30 for a litre of Penrite ten tenths oil or Silkoline that you squeeze through the filters - they also do aerosols which you are generally $20 for 3-400ml.

They also sell filter cleaner at about $15 a litre.

There are then about 50 other brands - Castrol, NoToil, Nulon, Motul, k&n, Maxima, etc

So yes, thats why I just grab the $12.99 2l bottle of chain oil from Aldi - its dyed blue so you can see where it is and isn't on the foam. Most Aldi's still have a few bottles left from the last special buy, but they are having it again when the mowers are out next saturday.

GA spares actually do distribute Maxima - again most mower shops charge $16 - $20 for the aerosol.

A mate of mine does bike racing (enduro and motorcross I believe) - he uses Maxima Fab1 or Motul I think. But he has admitted that he once used bar oil to get out of a bind

Those prices are crazy Tyler. No thanks.
It's bar oil for me, especially with an old beaten up Briggs!

Just got 2 of these, going back for another 2 tomorrow - cheapest I have ever seen it

Castrol semi-synth 15w40

should get 16 briggs/honda 600ml changes out of 2 bottles - $1.5 per oil change is good enough for me

Also Bought a 5l Penrite bar oil at SCA for $25 on clearance - normally 44 at repco. Good for the saw and air filters
Penrite bar oil

They do have castrol 30w on clearance for $4 per l, but not much stock around
sae30

Hi Tyler

Great price for the 15w40, last time I went and got oil on special with a limit of 2 per customer I asked the chap if I was able to buy more if I had a split personality ? he laughed and told me to grab another one.

Cheers
wce

Hey Tyler, can you put semi synth (or indeed full synth) into an older car that normally just takes mineral oil as long as the viscosity rating is the same? I wish there was an Auto Barn near me. That incredible. I must go try and locate one.

Technically yes, however, apparently it can loosen muck that was previously preventing oil leaks, so some say they start springing leaks once you put synthetic oil in.

Personally, I use GTX 20w50 and change it 2-3 times a year

Also synth oils tend to be higher ratings - eg API SM, SN, SN+. One thing they have done is reduce the Zddp (zinc) additives as they bugger cat convertors. Technically, this means cars with solid lifters are more susceptible to wear of the cam or lifter

That means most small engines (like briggs) could technically see more wear with high grade synthetic oils

But given the fact we see old briggs last 20 years on 500ml of sludge, I dont think the effect will be that great

Thanks man. I'll stick to Penrite Vantage premium mineral 15w40. My car engines run noticeably smoother on it than any other oils I have run in them, particularly the 302 Windsor in the Fairlane. Definitely worth the extra spend.
An old clapped out flathead Briggs would feel like it's having a spa with that stuff!!