I bought a 1994 XR650L a week or two ago. The bike runs fine but was neglected for years and now needs simple work. Well the last day or two I was riding it and while riding it starting jerking and puttering kinda violently. Similar to when you are in way to low of a gear, or running out of gas. The only problem is that it was neither of those. It has plently of gas, and I know how to ride so it was in gear properly. Now the bike wont start. It cranks and cranks but no start. What could it be???? Spark plug???