Hello I have a 16hp briggs and I think I have a primary clutch problem and I,m not sure how to fix it. Most of the clutch movement appears smooth except when it is at low rpm's When I start my machine the clutch will quickly engage and the engine doesn't like to idle. It does the opposite when I let off the gas it starts starts to open up smoothly then when the belt is almost at the bottom the clutch just pops in and no matter what I do the motor will not idle. Any advice will be appreciated. thank you