This article will cover the soft fixes you can complete if the pull cord of your petrol lawnmower won't pull.


TABLE OF CONTENTS


The pull cord can get stuck for a number of reasons:


1. Freeing the engine from its compression stroke

Tools needed


  • Spark plug tool

If the engine is stuck in the compression stroke, it may be making the starter cord difficult to pull.


This is because the piston has stopped in its compression stroke; you are pulling against the engine compression.


Please go through the procedure below to release the engine from its compression stroke:


  1. Remove the spark plug cap (the thick black cable at the front), pulling it off the spark plug.
  2. Using the spark plug tool, unscrew the spark plug in an anti-clockwise direction to remove it from the engine.
  3. Hold the start/stop lever (at your handle) and rotate the blades by hand 4 to 5 times, making sure that you are protected with gloves.
  4. Screw the spark plug back in by hand to prevent cross threading and tighten with the spark plug tool.
  5. Refit the spark plug cap, ensuring it clicks into place.

You should now find that the starter cord pulls out freely.


2. Checking the oil is at the correct level

If no oil has been added to the engine, the piston has no lubrication and can therefore seize up.

  1. Please check that the oil is between the minimum and maximum mark on the dipstick.
  2. If the dipstick shows there is no oil in the crankcase, add the recommended oil for your lawnmower.
  3. Then put on some protective gloves and gently push the mower blade until it turns.


Purging excess oil from the cylinder

Overfilling with oil, jolting or tipping the mower can lead to a hydro-locked engine, which means the oil has leaked into the cylinder head and can not be compressed.


If this is the case, we would recommend you to remove the spark plug and pull the engine over to purge the oil from the system:


  1. Remove the spark plug cap (the thick black cable at the front), pulling it off the spark plug.
  2. Using the spark plug tool, unscrew the spark plug in an anti-clockwise direction to remove it from the engine.
  3. When the spark plug has been removed, you may pull the engine over (by pulling the starter chord) to purge any oil from the chamber.
  4. Clean the spark plug thoroughly and refit it to the engine.
  5. To refit the spark plug, firstly, hand-tighten the plug in order to prevent any cross threading.
  6. Tighten the spark plug with the spark plug tool and refit the spark plug cap.


3. Checking that under the deck is clear of any grass or debris

If there is any grass, debris or twigs on the underside of the housing, it could potentially catch or bind on the drive shaft or between the blade and the housing.


This could prevent the blade from turning and prevent the starter from turning as the blade shaft is connected to the crankshaft.


  1. Please make sure that the underside is clear of any dirt or debris.
  2. When the underside of the lawnmower is clear please attempt to start the lawnmower by pulling the starter rope whilst depressing the brake lever on the handle.
  3. If you forget to pull the brake lever while pulling the starter rope, the engine will not start.


4. Cable tension

  • If the stop/start cable is too slack, then it won’t disengage the engine brake correctly, causing the pull cord to be under more tension than usual. Please tighten it, following the instructions given in 'I am having troubles starting my machine' / 'Starting Issues'.

5. Self-propel drive belt

  • When the drive belt slips off between the blade adaptor and the engine, it causes friction on the engine crank. Please refit the belt, following the instructions given in 'Replacing drive belt'.


6. Mechanical failure

 If your pull cord is still stuck, and none of the previous steps have helped you, then it is most likely that your starter mechanism has broken. You will need to replace the part with a new 'Starter Assembly', which includes the cover, cord and recoil mechanism.


If you have a Briggs & Stratton engine, then you will need to contact your local Briggs & Stratton dealership to order the replacement part. See this dealer locator.


If your machine is other than Briggs & Stratton (ie. SV150 or SE475), please contact our helpline or email us, and we will supply you a starter assembly.