Honda GCV135?

I have a HONDA GCV135 engine on a Quick Silver 46 SD Self Drive lawnmower, (about 12 mths old). I have lost the spark depressor, (conical mesh piece that sits in the exhaust), and since this happened I cannot get the engine started. After about 3 pulls on pulcord the fuel start to come out the exhaust. Despite replacing the spark plug, (which is sparking on test), the engine still wont even fire never mind start. A local dealer / repair shop owner, told me that the "spark depressor is unnecessary and the problem is much more serious. Could you please offer me some advice on how to sort this out. Thanks.