hi, i had this same problem with my 05 raptor 660. I cleaned the air filter, put new gas, and changed the oil. Now it runs just fine. So i dont no mabey this will help.

 

thanks will try that first , checked on new rev box this morning it is a little over 400.00 so we will try other things first .

 

So you rebuilt the carbs? Did you check your float bowl heights? Check your main jet sizes, and or needle height. Take air filter off for a short run, and see if that helps, if so your main jet may be too rich. Check spark plugs, wet and black too rich. Should be light brown (like toast).
Hope this helps.

 

thanks