2000 600 SXR backfire

[Twinkies1]

Hi guys, new to the thread but not new to snowmobiling, I purchased a 2000 600 SXR with 4000 miles, after running the sled 20-30 miles the sled seems to load up, today it actually backfired throught the exhaust, I went through the carbs twice, I was wondering if this sled had reed valves and if so maybe they are getting bad? Thanks in advance for the help, Brian

 

[Whammy]

I would go through the carbs again per tech page,,,,,,, have to remove components and clean throughly,,,,,,,, you can check the reeds when you have the carbs pulled,,,, also need fresh gas,,,, drain the old... should be good to go,,, fresh plugs of course, along with a good belt......... oh ya clean clutches also........... warm it up then hammer down,should hit 95mph,,,, hang on and be safe..........Welcome to TY........