I am running the same class and I use a Horstman dry clutch. I use the three -disk and it is not worth the money. A two disk dry clutch is the way to go. I would say to use either a Patriot clutch that is made by Comet Kart Sales or a Tomar clutch. The TD-23 (Tomar) is what most people in Yamaha run. We had a racer this weekend do the same thing that you did with the same clutch.
I have been racing for two years now, I know about the motor quite well. The guy that ones it never raced it and bought it from a guy that raced it a hand full of times. What should the number says to tell what year it is?
The kart is between 5-6 years old. It has a KT100 on it. Do you know how to tell the model year on the kart. Also what should I pay for it. The seller wants to know what he should sell it for.