So Why is It ...

[Gunny]

They supply you 4-cycle motor oil for a 2-stroke lawn mower engine?

Inquiring minds want to know. :)

[sundaydriver]

Are you talking 2 cycle motor in which you mix oil with gas?

[LongTermGuy]

Two cycle oil is never added to a crankcase. It is only added to the gasoline. The gasoline is then added to the fuel tank. The 2 cycle oil must be carefully mixed in a proportion - read the bottle....2 CYCLE oil is for treating GAS on 2 CYCLE engines. Your mower is probably NOT a 2 cycle (unless it's rare). Standard ENGINE OIL is used for lubricant on 4 CYCLE engines.

Four cycle oil is only added, poured, into the crankcase of the engine.
Four cycle oil is never added to the gasoline.

Most lawn mowers are four cycle.

[NightTrain]

Didn't you say that was a Briggs & Stratton?

To my knowledge, they never made a 2-stroke... I've only seen them put out 4-strokes. You don't see a dipstick?

[NightTrain]

Looking at the Briggs site, they're saying they made a limited amount of 2-stroke engines for lawnmowers up to 1991... all are 4-stroke now.

Curiously, they started making 2-strokes again for snowblowers.

http://www.briggsandstratton.com/us/en/support/faqs/2-cycle-engine-gas-oil-mix

[Balu]

Two cycle oil is never added to a crankcase. It is only added to the gasoline. The gasoline is then added to the fuel tank. The 2 cycle oil must be carefully mixed in a proportion - read the bottle....2 CYCLE oil is for treating GAS on 2 CYCLE engines. Your mower is probably NOT a 2 cycle (unless it's rare). Standard ENGINE OIL is used for lubricant on 4 CYCLE engines.

Four cycle oil is only added, poured, into the crankcase of the engine.
Four cycle oil is never added to the gasoline.

Most lawn mowers are four cycle.

You are speaking about old, classic 2 cycle engines' lubrication system. The modern (used somewhere from 70-x) looks like this. There is no need to prepare a fuel mixture in a fuel tank. And you see some oil is passing to the crankcase to lubricate crankshaft bearings on the intake-compression stroke of the engine.

http://tool-land.ru/image/rabota-chetyrekhtaktnogo-dvigatelya-i-dvukhtaktnogo6.jpg

Separate lubrication system of a two-stroke engine:

1 - oil tank
2 - carburetor/electronic injection system
3 - a splitter of a throttle cable
4 - throttle
5 - feed control oil cable
6 - piston metering pump
7 - a hose, the oil supply to the inlet duct.

The requirements to the lubricating ability of the oils differ, as in 2 cycle engines oil is burnt together with gas.

[Gunny]

Are you talking 2 cycle motor in which you mix oil with gas?

Yep.

[Gunny]

Didn't you say that was a Briggs & Stratton?

To my knowledge, they never made a 2-stroke... I've only seen them put out 4-strokes. You don't see a dipstick?

Guess you missed shop in the 8th grade. :laugh:

There is no dipstick. Except for maybe FJ:laugh:. There is a crankcase though.

[NightTrain]

Guess you missed shop in the 8th grade. :laugh:

There is no dipstick. Except for maybe FJ:laugh:. There is a crankcase though.

I'm well aware of 2-stroke vs. 4-stroke... been dealing with them all my life. Just not sure how knowledgeable you were, so I was trying to keep it simple! I have more 2-stroke toys than I do 4-stroke, by a long shot.

I really seriously doubt you've got a 2-stroke mower, unless that baby is 40 years old - my concern was that you misidentified it and were about to seize it by mixing the gas and missed the oil fill cap on the block. That happens more often than people think!

[Gunny]

I'm well aware of 2-stroke vs. 4-stroke... been dealing with them all my life. Just not sure how knowledgeable you were, so I was trying to keep it simple! I have more 2-stroke toys than I do 4-stroke, by a long shot.

I really seriously doubt you've got a 2-stroke mower, unless that baby is 40 years old - my concern was that you misidentified it and were about to seize it by mixing the gas and missed the oil fill cap on the block. That happens more often than people think!

Nah. I'm over 40 years old. :laugh: I learned my lessons on a 2-stroke.