Sorry if i have posted this to the incorrect place, I am just new to the site...

I have a briggs stratton lawn mower which i bought from B&Q about 18 months ago...

its worked perfectly until i lent it to moy brother who has just moved into a house with an overgrown 80ft garden! now when i try to use it it seams to surge (i.e. nearly cuts out then revs then nearly cuts out again) i`ve cleaned all the gras that I can see and also removed the air filter and cleaned that. it seams to be using loads of petrol...

the little arm that controls the revs is going backwards and forwards all the time trying to keep the revs up. (sorry thats probably not the technical term for it!!

any advice you can give would be great!

cheers