Small Engines (Lawn Mowers, etc.): MY Sled, polaris indy 650, crankcase pressure

Question
I have  1989 Polaris Indy 650 and it runs but sprays gas out of the carb into the air box. at one point it caught on fire. what should i do.
Thank you for your time.

Answer
There are a couple of things that generally caused fuel to spray back through the carbs.  If the engine has reed valves, one of them may be bent, stuck open or damaged in some way as to allow crankcase pressure to travel into the intake.  The other is a flooding condition caused by a problem with the needle/seat/float assemblies or dirty carbs.  Hope this helps.