About 2 weeks ago I bought a 2007 yfz450 that has been sitting for close to a year. when I got it I drained the gas and a friend of mine re-jetted my carb, cleaned it and added the "zip-tie mod". It has been running amazingly for about 2 days and then yesterday it started backfiring and it just quit when I was driving it around my neighborhood. I let it sit all night and figured it would be better this morning, but after riding it fairly hard for 5-10 minutes it just quit and wont start. I'm really new to this sort of stuff so any help would be appreciated.
PS..When I got it my water pump was leaking coolant so I replaced the outer seal and it seemed to fix it. I am not sure if this would have anything to do with it or not.