Qualcast 41cm Hand Push Petrol Lawnmower And Trimmer Briggs & Stratton 125cc

I am selling Qualcast 41cm Petrol Lawnmower Briggs Stratton 125cc together with a trimmer. Came as a combo from Argos, purchased September 2017 at around £200. I used it 15 times max, so all parts should be in good condition. I just struggle to get it started, first time it was the trimmer, I took it to a friend, who cleaned the spark plug, it worked fine, but after the winter break it won t start again. Same thing happened with the mower this spring. Couldn t get it started, it choked once but wouldn t keep running. Eventually while I was pulling the cord, it got unhooked and retrieved into the hood and now it won t come out quickly. It comes out little bit at a time. Hopefully it would be an easy fix for someone who knows what they are doing. I don t have the tools or time to play with it, empty petrol etc. so I am going back to electric. Collection in Sutton only