# Forum Home Renovation The Garden Shed  2 Stroke Brush Cutter Leaking Black Oil

## mojorising

I got a cheap 2-stroke petrol brush cutter a month ago off ebay and it started dripping black oil after a week. 
It seems to be coming from the join where the clutch assembly meets the motor. 
Do 2-stroke brush cutters have transmission oil? 
If it leaks is that just need tightening up or does it indicate a design fault or need a gasket? 
I though the only fluids in these machines were fuel and 2-stroke oil and grease on the end of the drive-shaft.

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## Bart1080

check and tighten all bolt on the motor.  Will be the oil in the 2 stroke mix.  
Not the first time I've seen these bolts come loose on a cheap piece of equipment

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## droog

How much oil in the two stroke and do you mix it before use ?
I assume the cut-out in the cover of the first pic is the exhaust and looks to be where the majority of oil is pooled.

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## mojorising

> How much oil in the two stroke and do you mix it before use ?
> I assume the cut-out in the cover of the first pic is the exhaust and looks to be where the majority of oil is pooled.

  Thanks for the replies Bart and Droog 
The 2-stroke mix is about 1:35 well shaken 
The 2-stroke is green but the oil leaking from the machine is almost black. 
Do brush cutters have oil as part of their clutch assembly? 
This is the machine  https://www.ebay.com.au/itm/130733499764 
It is quite powerful and feels quite sturdy but the oil leak is a worry

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## Bart1080

> Do brush cutters have oil as part of their clutch assembly?

  No, the only oil is within the 2 stroke mix.  Take the spark plug out.  Is it black with oil like it hasnt fired correctly?  Clean and try again.  If its not running smoothly, could be:  the Mixtures arn't set correctly, Assume it starts nicely and isnt spluttering when full power like the 2 mixture screws are set to and overly rich mix?check for broken gaskets on the cylinder heador loose bolts - check carby isn't loose, head bolts etcspark plug needs cleaning as its gunked up with oil/carban or replacingCheck the spark arrestor gauze isnt blocked, clean if req.  
The black oil is the burnt carben mixed in with the oil mix (normal).

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## Whitey66

It looks to me like you have your oil to fuel ratio too high. 35:1 is 28.6 ml in one litre, 143 ml in 5 litres, 286 ml in 10 litres and so on. Are you using an oil that came with the brush cutter? If you are, ditch it and get some proper good quality 2-stroke oil for air cooled engines.

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## droog

Two stroke oil may be green but once it is run through the engine and combustion process it picks up carbon, just like the oil in your car goes in a light honey colour but when you do an oil change it is black as. 
Too much oil in the fuel mix will give you black oil out the exhaust just like pictured. Cheap machines they usually advise higher mix ratios and you will always get discharge from the exhaust. 
My bet is the fuel / oil ratio, from the link the seller recommends 25:1. Compare to a quality two stroke like Stihl who recommend 50:1
The extra oil has to end up somewhere.

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