Hayter Harrier engine problem?
 

I have a Hayter Harrier 48 push mower. Its a year old, but I'm a gardener, so it gets a lot of use.

In the last few days, as soon as I get in to any long grass that it cant handle, instead of clogging up, then dieing, it just dies immediatly, with no warning. Is this a sign that the engine is on its way out, or is it repairable, and if so, whats the problem?