SF versus SL 10W-30 oil.

If dealing with a dealer does'nt he sell the oil , Other wise read the manual and follow it Don,t use 10/ 30 as it is not for small engines.

Manual specifies 10w-30, only SFor SE; but I figure they haven't even been made for years.

SL is newer and very much ok where SE or SF is specified. You see, "L" comes after "E" or "F". The oils are always backwards compatible.

But what if the engine isn't running backwards?

:)

Exactly. SL includes SF.

The engine doesn't have to run backwards. Just put the bike in Reverse.

In that case just use 80w90

As other say SL is the newest level oil and I expect exceeds all previous.

I myself use nothing but 5W30 Mobil 1 in my Honda Generator and all other air cooled engines. Air cooled engines usually run hotter and Synthetics can take a lot more heat without breaking down. Another advantage is that synthetics don't need the Viscosity Improvers (that don't provide much lubrication). Don't worry about the 5W classification. That means that at 32 F it has the same visosity as straight 5 weight at that temperature. That is thicker than the oil is when it is at operating temperature.

There are many web sites that get into extensive details about oil. For example:

...

That recommendation is a few years out of date. Many if not most small engines manufactured today are designed for multi weight oil.

The "S" means Spark (gasoline) [opposed to C which means compression (diesel)]. The second letter is 100% backward compatible, that is the later letters (what will be do when they hit Z?) The later oils can do everything the earlier ones did and more.

This is top-notch advice on the synthetic.

SL supersedes & replaces all SK & earlier rated oils and is fine.

Rob

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Tom

What question? Who are you responding to? What are you talking about?

Rob

For air cooled engines, it's important to use a good quality oil. Air cooled engines run hotter than liquid cooled. My fav is Castrol. So a good name brand is more important than the S rating. Other good brands I like are Penzoil, Mobil, and Exxon.

Briggs and Stratton reccomends.... HD30 weight for summer, and

Then you'd need LS oil, or ES or FS oil. Maybe even GS.

Or 03w01? That should be backwards compatible.

Any engine needs a oil of at least the quality specified...air-cooled or no.

As for the name on the can, if it meets a specified API/SAE grade, it meets the grade. The rest is advertising hype for the most part.

That said, there are a few oils I _won't_ use -- QS is one. No way to prove it really had anything to do with it, but I had a Chevy 350 throw a rod w/ it -- when opened it up, the top of the head was 2 inches deep in sludge and blocking the oiling holes so it wasn't getting any oil at all down no's 7 & 8 and the rest were ready...never overheated, always changed on schedule, etc., etc., ... But, at

Also for an air cooled/flat tappet engine you might want to look for a "fleet" oil (both gasoline and Diesel rated) and also one NOT rated CJ-4 (the latest Diesel rating.) The newest oils actually have fewer zinc compounds (usually ZDDP, an anti-wear additive) per the new specs.

A motorcycle oil might be a good choice, as well...

nate