So i recently purchased a crf 80. It is completely stock. When i bought it, it ran very well for about a week. The bike pulled hard and performed the way I expected and I did a LOT of riding that week.
Then, One day, after a few hours of continuous riding, I noticed that pulling the throttle past 1/3 of a turn would cause the engine to bog badly. This was an instantaneous problem because 2 min before that, I was riding it hard and it was doing fine.
Now, regardless of how slowly I turn the throttle, there is a point (about 1/3 turn) where the engine will stop providing power. Whats weird is that idle is fine and so is low end rpms. Any ideas? Think I should clean out the carb and check out the spark plug etc. Anyone have any idea what the problem could be?