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How To Troubleshoot A Non-Starting 2-Stroke Engine

Most petrol hand tools will be powered by a 2-stroke engine and while they are in some ways easier to use and lighter than a 4-stroke engine, they can still give the keen gardener a bit of trouble.
One of the most common problems is an engine that won’t start. Here are some basic things to check if you are having trouble:


As with most petrol engines often the reason for not starting is a problem with the fuel. Check you have fuel in the machine first. If it is old fuel, then it is worth draining and refiling with fresh fuel. Petrol goes off after only a few weeks and engine performance will drop. 2-stroke engines are lubricated by having the 2-stroke oil mixed in with petrol. It is important that this mix is done carefully as an incorrect ratio can lead to engine problems. Always check the manufacturer’s guidelines in the manual.
Check the fuel lines for wear or kinking to make sure fuel is getting into the engine.


If fuel is not the problem, then the next thing to check is the spark plug. Usually this is removed by unplugging a rubber cap and then using a spark plug wrench to unscrew it manually. If the business end of the spark plug is dirty, then it will need cleaning or replacing. If the plug is damp then fuel is likely to be getting through. If it is dry then no fuel is getting through and this could be your problem.


Check the air filter. Over time dust and oil particles can build up in the air filter and this can impair the performance of the engine. Usually this is easy to remove and replace. Sponge air filters can be washed and replaced when they are completely dry.


If none of these reveal the problem, then the next thing to check is the carburettor. This small piece of machinery mixes the fuel with air before sending it to the sparking chamber. On older machines this can get clogged with fuel deposits which need to be cleared out. It can be straightforward to do this but if you don’t feel confident this is the time to get your local service agent to take a look.

Servicing and Maintenance

As with all petrol-powered machines, you are advised to get it serviced regularly (usually once a year) and keep on top of maintenance. Some machines will have a conditional warranty that requires the machine to be serviced annually. 
If you aren’t going to use the machine for a long period, say over the winter months, then it is best to drain all the fuel out. This will help prevent build up in the carburettor and will ensure you use fresh fuel next time.