2008 Suzuki King Quad 400FS Backfiring

[GaKingQuad400]

My new KQ just suddenly started backfiring VERY loudly sometimes when I get out of the throttle at a good speed and let the motor help me to slow down along with braking. It also will make a soft backfire if I rev it up a little in neutral, and the last symptom it has is when I get it up to temp and let it idle it will purr like a kitten and all of a sudden just shut off intermittently. I already bought a new plug, gapped it, installed it and if anything it made it worse. I did have the 100 mile service done not long ago and it just turned 400 miles today so it leads me to believe that it may be running just a little lean but I wanted to run by everyone here to see if anyone else has had this happen and if so, how you remedied it.

[bansheedr]

Sounds like it needs a little rejetting to me.

[Ajmboy]

I'm assuming this has a carb and not Fuel Injected like it's big brother...

Sounds like it's running out of fuel in the carb bowl. Has this quad sat for a little bit or have you been pretty regular riding it. It's a 2008 and they're almost at 2010 models....so it's 2 years old. Maybe the carb needs a cleaning?

[GaKingQuad400]

I guess I should have mentioned that it has a carb but no, it hasn't sat very much at all. I just purchased it a couple months ago and ride it regularly either at the house or at our hunting lease a couple days a week. Wish I could find a clymer manual for it so I would feel comfortable removing the carb bowl to check for trash. Anybody have any links or pics on removal of a Keihin CVK32 carb?

[Ajmboy]

I have pics of carbs on other 400 series atvs...which may use the same carb. I would definately invest in a manual.

[DirtDemon]

How is your air cleaner? Have you checked the valve lash? The manual is a good idea.

[handyhiker]

It is possable that the fuel pump vacume line has a leak. If this happens, the fuel pump doesn't work well and air is introduced making the engine run lean. Assuming of corse that this machine has a fuel pump . Also if it has a vacume fuel petcock, check that vacume line as well.