Thread: Two stroke oil

Originally Posted by rocket scientist

Just been to our local Stihl shop to pick up a part.
Since my 4 ltr bottle of 2 stroke oil is near the end after a few years I had a look at the price of a new bottle.
Stihl now have a range of three types of 2 stroke oil, standard up to super synthetic at about $140 for 4 ltrs.

Any comments on the different grades, and the difference if any between Stihl and other cheaper brands?

Pete.

Firstly, buy smaller containers. Leaving the oil sit around for "a few years" is not great, and makes discussions on the relative merits of different 2ST oils a bit moot.

2nd - Stihl 2ST is a rip off.

I use penrite or just the (McCulloch?) brand that bunnings sell.

Originally Posted by isuzurover

Firstly, buy smaller containers. Leaving the oil sit around for "a few years" is not great, and makes discussions on the relative merits of different 2ST oils a bit moot.

2nd - Stihl 2ST is a rip off.

I use penrite or just the (McCulloch?) brand that bunnings sell.

Yeah, I get the impression that like most products we buy, they are all from the same manufacturer, but with different labels.

Originally Posted by rocket scientist

Yeah, I get the impression that like most products we buy, they are all from the same manufacturer, but with different labels.

This is not completely true, e.g. I am sure penrite make their own semi-synth 2ST oil. However I am sure someone makes 2ST for Stihl as they are not an oil company.

However most of the developments in synthetic 2ST oils are about reducing emissions and providing most stable fuel mixes rather than providing better lubrication.

Originally Posted by isuzurover

This is not completely true, e.g. I am sure penrite make their own semi-synth 2ST oil. However I am sure someone makes 2ST for Stihl as they are not an oil company.

However most of the developments in synthetic 2ST oils are about reducing emissions and providing most stable fuel mixes rather than providing better lubrication.

Thanks for that.
There was rumour over hear some time ago about banning 2 stroke outboards on the lakes. I think the new technology of 2 strokes won in the end.
Pete.

A mate of mine who use to own a small engine / garden / chainsaw shop told me that if you are mixing 40:1 you need to use full synthetic if using mineral base stay with 25:1 ratio even if the manufacture states a 40:1 ratio. Worse he said that could happen is you foul plugs if that happens drop to 30:1.
In his business he has seen too many melted pistons from people mixing 40:1 using mineral oil.

Me I use the cheap mineral based 2st oil from the hardware stores. It is cheaper in the dedicated 1ltr bottle than the the 1ltr with the inbuilt measuring area.
Have not had any problems to date.

Recent advice from a Garden Power-tool shop. - Biased more for the heavy & enthusiastic user than the occasional handyman...

- "Use a synthetic - based, (preferably fully ) two stroke oil. Brand is not the be-all and end-all, it's all about burning clean(er) and less carbon/gunk building up.

Buy and make up fuel as you need it rather than store it for ages.... - a week or three is fine, but a couple of months in the back shed is not recommended... Mixed or Unmixed.

And 95/98 in preference to 91. Reason:- Contains more cleaning agents than 91. For the home-gardener this extravagance may add a whole Dollar to the week-end. "

I use the blue-greenish Stihl oil, fresh 98 and only mix 2 litres at a time. - a Saturday's max. useage in the weed-snipper/blower.

Neither spark plug has been changed for years... and they start & run fine.

My 2 cents worth...

That $140 oil, don't bother, thats what you'd probably pay for Shell M which is designed for 22,000rpm racing 2-strokes.

I would just stick with a regular mower/edger type 2-stroke synthetic which will burn clean and not clog up your filters, and I always mix 25:1 for everything to preserve the motor. At 25:1 I've never had any problems, I would get occasional probs at about 16:1 when I used get rid of racing 2-st through the mower and edger - OMG it smelled good!

For fuel, I don't think it matters what you use. The motors are so low in compression and so little fuel goes through them. If the premium fuels have better detergents as Superquag says, then all the better, but remember the premium fuels are a lot more carcinogenic than regular and even racing fuels to both touch and breath. I actually think the biggest problem with the fuel system is the oil residue in the carby when the fuel eventually evaporates off. This makes all of the rubber flap valves stick shut until you can get fuel flowing through them again and the glaze will eventually build up - I guess this is exactly what superquag is talking about too. For Victa mowers, I shut the fuel off and run them out.

re fuel, just don't use anything with ethanol in it, or if you do, use it all up quickly, don't let it sit for any longer than a week. Back in the bush my old mate who had the OPE workshop (and did the Stihl dealers warranty repairs) hated E10 fuel with a vengeance, it absorbs moisture and breaks down rapidly and makes a real mess inside tanks, carbies and engines.
For that reason I use BP Ultimate, but my saws have been, err, tweaked a little too.

The syn oils, especially those that meet JASO FC/FD, burn a lot more cleanly than most mineral based oils.
Less carbon in the chamber and the piston crown is a good thing, and there is also less plug fouling.

Stihl Ultra is a rip off, it used to be blended by Castrol in Europe for Stihl but they also had a blender in the US, can't recall ATM who it was.

I used to use Castrol Power 1 Racing TTS years ago, cheap for a syn and readily available but it stung and irritated my eyes, so I went all out and use Motul 800 2T for saw use, it smells like banana's when mixing, the fumes don't irritate and it burns cleanly, and I used Penrite for the el cheapo whipper snipper, mixes well and again, doesn't irritate.

Even though the Castor based oils smell great, it leaves too much residue.
Karts need the protection it gives, OPE stuff just doesn't rev hard enough.

I used to dump my old race fuel in my road car, you get all sorts of looks at a set of traffic lights.


re mix ratio, I'm in the more is better camp too, as long as you retune for it. 50:1 is for emissions and carbon fouling, but if you run your gear hard and it's tuned properly you don't get carbon buildup with richer mix ratios.