I took my 2005 Kingquad to the Suzuki dealer to have the CVT belt replaced. It wasn't holding back coming down hills like it used to. They did a compression test on the motor and said "It's not your belt that bad, it's that you have lost compression. This is due to the motor sucking in dirt because the air filter wasn't put on correctly."
There are several of us that have a Kingquad 700's. We compared the air filter box from the 2005 to the 2006. The 2006 air filter stem sits about 1/4" lower than the one on the 2005. The filter on the 2006 is easy to fit correctly, the one on the 2005 doesn't. Suzuki knows about this problem or they wouldn't have corrected it on the 2006.
Have any of you had experience in wriiting about this issue to Suzuki? Suzuki has had several recalls on the 2005 for safety issues but not performance issues. I would like to know if any of you have had this problem and how you resolved it? Did you replace the air box on the 2005 with a 2006 model.
If you have a 2005 model you should look at this problem.

 

they know about it ,

 

You should ask this question on Nyroc's king quad forum, I think some of them had to deal with this, there's a lot of King owners on that forum over 5000 topics over the past 2 years.