I bought a used 2008 King Quad 400 last year. When I bought it, it had 128 miles and didn't have a scratch or flaw on the bike. I rode it all summer and fall and it ran flawlessly. I used it this winter to plow snow. While I was plowing I started to notice bit of chirp when in 4 wheel drive. If I am at stand still and turn on the 4 wheel drive (and give it a few seconds to engage), when I hit the gas there is a short chirp sound as the wheels start spinning. I didn't notice this last summer, but noticed while plowing and this weekend while out riding. Is the sound the clutch engaging, the four wheel drive engaging, the belt gripping/slipping? The bike runs great and doesn't slip or seem to loose power under load like it would if the belt was wet or muddy. Also, I have not heard the sound at all when in two wheel drive. Does the clutch/belt work any differently when in 4 wheel drive? Is this a normal sound on the Suzuki's or is it something I need to have checked out? Thanks!

 

I have changed the oil and front and rear differential fluids within the last month and the sound is still there!

 

My 2 cents worth of advice would be to pop the belt cover and check the belt.
Normaly slipping belts will cause chirping noises.
The width of the belt could be worn down, or possibly your engine idle is a bit high
causing the clutch to engage slightly rubbing the belt when idling causing it to get hot.