Tag: fuel

2 Stroke tools and the dangers of modern fuel

In order to maintain a garden a few basic tools are required.

  • Lawn mower
  • Hedge cutter
  • Trimmer / edger
  • Chainsaw (optional)

Whilst electric tools with a mains cable are suitable for the smaller garden / yard when the size increases you find the tools underpowered and the cable a pain. In this scenario it is common to use 2 stroke tools for things like hedge cutters / chainsaws.

So what exactly is a two stroke engine and how does it differ from a regular 4 cycle engine ? Without going into the technical details the main difference as far as most people are concerned is that engine is simpler, the fuel being a mix of petrol and oil and more importantly for many gardening tasks the engine is able to operate on it’s side and upside down without stalling.

Whilst this offers many advantages the introduction of ethanol in most modern unleaded fuels causes many problems to gardeners with these tools. In the UK it is now more or less impossible to buy any fuel from a garage which does not contain ethanol, even the premium unleaded with a higher octane rating still contains ethanol.

I first became aware of this issue when my multi tool kept stalling whilst cutting a hedge. I found that by tipping the machine to one corner I was able to keep it running. Upon closer inspection I noticed that the fuel supply line inside the tank had perished and that the line was now at such a height inside the tank that the engine was unable to get any fuel. The fuel line looked very similar to the pipes I had used on radio controlled cars as a child, so I visited a model shop and bought a few metres of fuel line and set about replacing the fuel line. After about 6 months I found the lines had perished again.

Frustrated with this issue I did some research and became aware that this was due to the ethanol drying out parts and causing this problem. I tried to buy premium fuel but found this made no difference.

The ethanol is a real issue for modern small engines. Unleaded petrol does not store well and should be used up within 3-4 weeks of purchase. If you wish to keep a jerry can of fuel for longer you should add a fuel stabiliser. This will help prevent issues with varnishes and getting a gummed up carburettor. After use the fuel should be drained from the tank and the engine run dry. If you have an inline fuel valve twist this and start the machine again until it runs out, this will prevent fuel sitting in the carburettor and forming a gum.

Many gardeners however only use their machinery occasionally, they use a few litres of fuel a year and want the machine to be reliable and minimise the amount of time when the machine is at a dealers being fixed / serviced. If this is the case I would recommend you simply purchase a premixed fuel. At the time of writing a litre of petrol is around £1.20 in the UK which equates to £5.40 a gallon. This fuel will keep for a 3-4 weeks before it goes stale and so the cost a fuel stabiliser should also be factored in. This is available from Screwfix and similar stores from £4 for 100 ml then there is also the cost of 2 stroke oil and the time spent mixing. If you are an occasional user does it make sense ? You still need to drain the tank after each use and run the machine dry. Instead I would recommend buying a premixed fuel which is both high octane and ethanol free and can be stored for 3-5 years with the fuel left in the machinery between each use. Stihl motomix or Husqvarna premixed fuels are readily available from reputable tools suppliers and online.

Using a premixed fuel works at around £20 a gallon which is 3-4 x more expensive than buying regular fuel from a petrol station. However for the occasional user does this matter ? How many litres do you use in a year ? How much does a carburettor rebuild cost ? How much time does it take to replace the fuel lines or how much will you be charge if someone else does this job ? How long can you afford to be without the machinery whilst it is being fixed ? In the height of summer having a tool at a dealers being fixed can soon mean that you fall being on routine maintenance and then on the back foot fighting a battle to try and get everything in order before winter draws in.

For the typical domestic user I believe that the convenience and fact that the machine will be more reliable over the long term make the use of a premixed fuel a no brainer.

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