Snowmobile Repair: snowmobile choking out, carburetor repair kit, yamaha srv

Question
I have a 1987 Yamaha SRV.  It starts great and runs excellent for about 15 minutes.  I am assuming that the sled is warmed up by then.  After 15 minutes the motor starts missing and heavy smoke comes out of the exhaust.  After a while longer it will eventually choke itself out and will not idle.  at this time I smell a strong fuel odor in the engine area.  I assume it is flooding itself getting to much gas.  I will wait a half hour or so and It will be fine for a while and act up when warm.  

Is there an adustment on the carburetor that will solve this?

Thank You for you time

Answer
Hello Eric,
 It sounds like inlet needle inside the carburetor is sticking, a problem that can only be fixed by getting a carburetor repair kit. Most dealers and Dennis Kirk, www.denniskirk.com or at 1800-328-9280, have the kits. You may want to replace the spark plugs afterwards since they are probably fouled from the rich running sled. If you do decide to rebuild the carburetor, and I'm assuming that you have a Mikuni carb, www.mikuni.com has diagrams that help alot with rebuiling the carburetor. If you don't think this is the problem, there is a small brass screw on the side of the carb that you may want to turn in a bit,( it's the air screw)to lean the mixture. I hope this information helps, Good luck with the sled! Mr.W