2 stroke oil to fuel ratio

[Eddy_t]

well im not sure what brand of oil i have, or the grade/specs as i bought it from homebase and it dont give any info on the container.

all i can tell you about it is, its red and its oil

chris.

 

Ah! Dustbin and buy proper trusty stuff, I seized two saws running 33:1 cheap crap!

 

On a similar note, running an oil rich mix will cause coking, overheating, and at worst, carbon flakes can break off and score the engine that way too!

 

 

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[Gerbutt]

As long as its a reputable oil you should be fine at 50:1

 

Brilliant, thanks for that 😀

[predator]

i thought all oil comes out the ground like trees do " & it also burns the same smokey :001_rolleyes:

[H-A]

If you increase the oil in the mix you will reduce the amount of petrol, the saw will run hotter and leaner with 33:1 rather than 50:1, the petrol vaporising in the cylinder prior to combustion also plays a large part in cooling the engine.

 

I do as the manufacturer recommends, each engine is different, for some of my outboard motors 10:1 is normal, the worst is 6.4:1, that does smoke.

 

Odd as it sounds you can get a lean seize from adding too much oil to the mix.

 

H-A

[Stubby]

Modern synthetic oils like Husqvarna XP are supposed to be 50:1 . I would not trust any " garden center " stuff . Bin it and get some proper oil from a saw dealer .....

[chrismechanic]

ok guys i hear you.

 

anyone want a bottle of slightly used homebase "really good" 2 stroke oil

[Eddy_t]

ok guys i hear you.

 

anyone want a bottle of slightly used homebase "really good" 2 stroke oil

 

Keep it for rebuilding the engines, I smear it on the inside of a cylinder when fitting a new piston

 

 

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[wyk]

Yep, all the oil makes it to the combustion chamber, & out through the exhaust, but it does not contribute to the combustion process, so less fuel & more oil in your mix actually results in a fuel deficiency in the air/ fuel ratio.

Now you got my head in a spin, but it is correct.

 

Oil has more BTU than petrol. The exhaust is blue because the oil combusted. Even 4 stroke engine oil would combust in the heat of a 2 stroke chamber, let alone 2 stroke oil. How clean it burns is another debate altogether. But it does burn. This is what attracted the attention of the EPA, afterall. As for rich or lean - you tune your saw for the fuel that is in it. The ratio is moot if you know how to tune the saw.

[peatff]

I run non synthetic at 33:1 and synthetic at 50:1 as recommended. Non synthetic makes a lot more smoke

[GardenKit]

Oil has more BTU than petrol. The exhaust is blue because the oil combusted. Even 4 stroke engine oil would combust in the heat of a 2 stroke chamber, let alone 2 stroke oil. How clean it burns is another debate altogether. But it does burn. This is what attracted the attention of the EPA, afterall. As for rich or lean - you tune your saw for the fuel that is in it. The ratio is moot if you know how to tune the saw.

 

Whilst it is true that oil does burn, it burns much more slowly than the fuel so it does not contribute to power. There would have been more power available from an equivalent volume of petrol. So if you overdo the oil you will lose power, as well as running lean on the air mix.

 

And yes, you can retune the carb to compensate, but to be fair, very few operators have the skill or tools to do this, so the mixture remains incorrect whilst they blindly carry on in a cloud of smoke with a poorly running engine.

 

Much better just to use a 50:1 mix of GOOD oil.