That stock engine is crap anyways, it won't get you moving with any kind of power and you'll have to push it up hills. Most people ditch the stock engines for bigger ones so just replace it with a 6.5hp engine, you'll be much happier with it. It wont struggle to get you moving and if its a Briggs, Honda, Honda clone, Tillotson or predator there will be upgrade options for more power if you want them.