Kawasaki Mule idle problem

[xr23]

I have a Mule 2520 with a recently installed rebuilt engine purchased from Princeton Kawasaki, in Inidana (I highly recommend them; engine looks and runs like a brand new engine). I have to blip the throttle to get it to return to low idle so I can shift the mule without grinding the gears. I know this is a common problem with the mules. Has anyone figured out what the trick is to getting the idle to return to low idle reliably without having the blip the throttle? I want it to always retrun to low idle to moment I take my foot off the gas pedal.