My Petrol Chainsaws engine is not working correctly

Step-by-Step Guide

Step 1: Safety First

• Ensure the chainsaw is switched OFF
• Allow the engine to cool if it has been recently used
• Work in a well-ventilated area
• Do not smoke or use open flames near fuel

Step 2: Check Fuel Age

• Use only fresh unleaded petrol (less than 30 days old)
• Old fuel can break down and cause:
  • Poor starting
  • Rough running
  • Engine stalling

If fuel is older than 30 days:

• Safely drain the fuel tank
• Refill with a fresh mixture before retrying

Step 3: Check Fuel-to-Oil Ratio

Ensure the correct 2-stroke mix is used:

40:1 ratio =

• 1000ml (1 litre) unleaded petrol
• 25ml 2-stroke engine oil

Incorrect ratios can cause:

• Hard starting
• Loss of power
• Engine damage or excessive smoke

Step 4: Restart the Chainsaw

Once fresh fuel is confirmed:

• Ensure correct fuel mix is in the tank
• Pull the starter cord to start the engine
• Disengage the chain brake once running
• Allow the engine to stabilise before cutting

Important Safety Information

• Always use fresh fuel (under 30 days old)
• Never run the engine with incorrect fuel mix
• Avoid fuel contamination or mixing old and new fuel
• Always disengage chain brake only after engine starts

Frequently Asked Questions

Why won’t my chainsaw start at all?

The most common cause is stale fuel or an incorrect fuel-to-oil ratio. The carburettor may also be affected by old fuel deposits.

What happens if I use the wrong fuel mix?

Incorrect ratios can cause poor performance, smoke, overheating, or permanent engine damage.

Can I just top up old fuel?

No. Old fuel should always be fully drained and replaced with a fresh 40:1 mixture.

How do I know if my fuel is bad?

If it smells sour, appears separated, or is over 30 days old, it should be replaced.

Should I adjust anything else if fuel is correct?

If fresh fuel does not resolve the issue, further checks may be required (air filter, spark plug, carburettor).