tt600 runs,dies, then wont start

[mikes6084]

hi i have a 86 yamaha tt600 that runs like a bat out of h*** but if you let it idle or come down to an idle it usual stalls after you have been riding about 10-15 minits weather you ride it hard or just let it idle.the main problem is when it does stall you have to wait about 15 minits before you can start it and it starts in 1 or 2 kicks. when i pull the spark plug it is sooty,carburetor is still cold,still has very good compression,and piston is not stuck in the bore.

i have been working on this for a couple weeks and every thing that i see is saying it is too rich like sooty plug after stall and black smoke at and just off idle. but every thing i read about jetting a bike carb says the piolet jet is too lean.

i will try almost anything except buy new carbs