Briggs and Stratton 4 hp motor

[Edbear]

Still beats the once in a lifetime oil change most mowers get.

Oh, that reminds me...

Or does nine years old mean I'm still running it in..?

[Edbear]

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Actually, I beleive 10/40 is a little thinner than 30w when cold, and a little thicker when hot.

Remember one oil does not generally provide for less friction than any other, it's just how they perform in different circumstances: ambient heat, sheer forces, contamination, engine performance, that defines them.

A motor mower engine is a little less stressed than a motorcycle engine. It just sits there most of the time at a fairly constant low RPM with the occaision heavy load if your grass is long. It's not a highly tuned beast and therefor will last a long time if looked after (clean filter and oil).

Mmmmm! "A little thicker when cold and a little thinner when hot... not a highly tuned beast and will last a long time if looked after..." Sounds a bit like me, really...

[Laava]

http://www.briggsracing.com/display/...p?docid=101379

[Motu]

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(clean filter and oil).

This is actually the most important point,and I've mentioned it a couple of times - the B&S has NO oil filter.Modern oils have dispersants,often incorrectly called detergents,and these keep the contaminants in suspension so they can be transfered to the filter for elimination from the system.One of the reasons B&S recommend a straight 30 is because they are low in dispersants,they know that often these engines run their whole life on just the factory fill,mower maintenance is often nil.For the same reason classic bikes like Triumphs and Nortons etc use a straight weight oil - they have no filters either.Contaminants settle to the bottom and are flushed out on oil change.

[huck farley]

This is actually the most important point,and I've mentioned it a couple of times - the B&S has NO oil filter.Modern oils have dispersants,often incorrectly called detergents,and these keep the contaminants in suspension so they can be transfered to the filter for elimination from the system.One of the reasons B&S recommend a straight 30 is because they are low in dispersants,they know that often these engines run their whole life on just the factory fill,mower maintenance is often nil.For the same reason classic bikes like Triumphs and Nortons etc use a straight weight oil - they have no filters either.Contaminants settle to the bottom and are flushed out on oil change.

I don't think I will have to worry about suspension of hickeys in the oil Motu. I have a thing about changing oils in all my mechanical beasts. The mower gets an oil change at Christmas time, and again in June. I bet there is mowers out there 5 years old that have never had one. They soon pack up and the lawn owner has to buy another new mower.

[Fatjim]

mea

This is actually the most important point,and I've mentioned it a couple of times - the B&S has NO oil filter.Modern oils have dispersants,often incorrectly called detergents,and these keep the contaminants in suspension so they can be transfered to the filter for elimination from the system.One of the reasons B&S recommend a straight 30 is because they are low in dispersants,they know that often these engines run their whole life on just the factory fill,mower maintenance is often nil.For the same reason classic bikes like Triumphs and Nortons etc use a straight weight oil - they have no filters either.Contaminants settle to the bottom and are flushed out on oil change.

I meant air filter. This is really important because of the dust that floats around a lawnmower.

[McJim]

Hmmmmm - I've put 10W40 in the lawnmower....I wonder what will happen when I put 30 in the Ducati.....what fun.

[fuknKIWI]

You'll probably find that the briggs and stratton engine, being a fine example of american engineering needs a 30w oil just to fill the huge gaps in the bottom end. You may even find a banana skin to be beneficial.

Briggs & Stratton made in Milwaukee.
Guess who owns B&S?

[huck farley]

mea

I meant air filter. This is really important because of the dust that floats around a lawnmower.

I'm confused my engine oil doesn't go through the air filter. But if it did I would kill all the worms in my garden, and then the birds would starve, then the ants would have nothing to eat!!! Have I missed anything?

[xwhatsit]

I'm confused my engine oil doesn't go through the air filter. But if it did I would kill all the worms in my garden, and then the birds would starve, then the ants would have nothing to eat!!! Have I missed anything?

Because the air ends up inside your engine, which will do death to your bore, and contaminate your oil as well.

[What?]

I've kept the mower well maintained - air filters, clean SAE 30, good plugs, yahdeyah... And the bugger broke its piston the other day!
B&S engines are not meant to have maintenance...

[huck farley]

I've kept the mower well maintained - air filters, clean SAE 30, good plugs, yahdeyah... And the bugger broke its piston the other day!
B&S engines are not meant to have maintenance...

Well there you go If you had have been running fully synthetic this may not have happened, Bad luck mate, I hope it don't cost you to much dosh to get her up and running!!

[What?]

Nah, I reckon yours will blow up even quicker . B&S motors should keep the factory oil in them until death. In fact, I don't know why they have an oil filler or drain plug...

Oh well, I just hope the bore is OK - a piston and ring kit is pretty cheap. Probably throw new mains and big end in as well, then she'll be good for another 12 years.

[smoky]

the B&S has NO oil filter.Modern oils have dispersants,often incorrectly called detergents,and these keep the contaminants in suspension so they can be transfered to the filter for elimination from the system.

If I ever bought a second hand car and had no idea of it's service record, I would drian the oil and run it on diesel engine oil for a while, for a month or so, then change the oil and filter again. Oil for a diesel engine has way more detergents than normal and it really cleans out your engine well.

One of the reasons B&S recommend a straight 30 is because they are low in dispersants,they know that often these engines run their whole life on just the factory fill,mower maintenance is often nil....- they have no filters either.Contaminants settle to the bottom and are flushed out on oil change.

My old lawn mower had a Tecumseh engine – never changed the oil in 12 years, motors now running a friends go cart because it out lasted the mower body.

[smoky]

What I would like to know is. Would the left overs from an oil change be suitable to use in my Briggs & Stratton 4hp motor mower engine when it requires an oil change, which I do twice a year. The book says to use B&S SAE30 oil. Would a fully synthetic oil fuck the B&S engine. Or would the engine benefit from using clean fresh 10-40 fully synthetic oil. A little feedback please.
Cheers HF

Of course you can use a multi grade synthetic in your old B&S. Oil grades are based on a viscosity range at a standard temperature; the higher the viscosity, the higher the SAE grade number. These numbers, which range from 0 to 50 or higher, are referred to as the "weight" of the oil.
The letter "W" is the oil's cold-weather weight, as in 10W, which is gauged by the oil's viscosity at 0 °F. The warm-weather weight is based on the viscosity measured at 210 °F.
High-molecular-weight polymers improve the viscosity and are added to oil base stock to create multigrade oils that maintain the ability of the oil at different tempretures. At cold temperatures the oil is thick and the polymers are ‘balled-up’, and at warmer temperatures they expand to prevent oil from thinning out too much, maintaining a constant viscosity and protecting your engine in all conditions.