Sea Foam works wonders. Before I would rebuild them I’d try it. At minimum, one full can, if not two, per full tank of fuel. Ride it 50-60 miles. Let it sit over night. Ride it again. And before any of you guys start hollering, you can run Sea Foam 50/50. Be expensive, but you can. Get in the habit of turning the fuel valve off after every ride.
Goid luck.