This article will cover the soft fix you can take if petrol is leaking from your primer bulb.


Note: this only applies for Sovereign, Challenge and Ryno lawnmowers, which all have the SV150 or SE475 engine.


If petrol is coming out of your primer bulb, this means that it is backing up in your carburettor and flowing out of the primer tube. The float-valve in your carburettor has most likely got stuck and just needs to be adjusted. 


Please try the following 'Bleed & Tap' procedure:


  1. Locate your carburettor. It is a metal lump about the size of your fist, on the other side of your air filter, in-between that and the engine.
  2. You will see two nuts, one at the bottom and one at a 45° angle. You need to loosen the angled-nut with a spanner. Do not unscrew completely. 
  3. Let the fuel bleed out from the loosened nut for about 20-30 seconds.
  4. Re-tighten the nut.
  5. With your spanner or a screw driver or similar implement, tap sharply a few times on the float-chamber of the carburettor. This will agitate the float valve, helping it shift back into the correct position.


You are now ready to start up your machine. The primer bulb fuel leak should be resolved.